# include <cmath>
# include <cstdlib>
# include <iomanip>
# include <iostream>

using namespace std;

# include "toms743.hpp"

int main ( );
void test01 ( int nbits );
void test02 ( int nbits, double dx, int n );
void test03 ( int nbits, double xmin, double xmax, int n );

//****************************************************************************80

int main ( )

//****************************************************************************80
//
//  Purpose:
//
//    toms743_test() tests toms743().
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    17 June 2014
//
//  Author:
//
//    Original FORTRAN77 version by Andrew Barry, S. J. Barry, 
//    Patricia Culligan-Hensley.
//    This C++ version by John Burkardt.
//
//  Reference:
//
//    Andrew Barry, S. J. Barry, Patricia Culligan-Hensley,
//    Algorithm 743: WAPR - A Fortran routine for calculating real 
//    values of the W-function,
//    ACM Transactions on Mathematical Software,
//    Volume 21, Number 2, June 1995, pages 172-181.
//
{
  double dx;
  int n;
  int nbits;
  double xmax;
  double xmin;

  timestamp ( );
  cout << "\n";
  cout << "TOMS743_TEST\n";
  cout << "  C++ version\n";
  cout << "  Test the TOMS743 library.\n";

  nbits = nbits_compute ( );
  cout << "\n";
  cout << "  Number of bits in mantissa - 1 = " << nbits << "\n";

  test01 ( nbits );

  dx = + 1.0E-09;
  n = 10;
  test02 ( nbits, dx, n );

  xmin = 0.0;
  xmax = 1.0E+20;
  n = 20;
  test03 ( nbits, xmin, xmax, n );
//
//  Terminate.
//
  cout << "\n";
  cout << "TOMS743_TEST\n";
  cout << "  Normal end of execution.\n";
  cout << "\n";
  timestamp ( );

  return 0;
}
//****************************************************************************80

void test01 ( int nbits )

//****************************************************************************80
//
//  Purpose:
//
//    TEST01 compares WAPR to stored values.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    17 June 2014
//
//  Author:
//
//    Original FORTRAN77 version by Andrew Barry, S. J. Barry, 
//    Patricia Culligan-Hensley.
//    This C version by John Burkardt.
//
//  Parameters:
//
//    Input, int NBITS, the number of bits in the mantissa.
//
{
  static double dx1[68] = {
    1.E-40,2.E-40,3.E-40,4.E-40,5.E-40,6.E-40,7.E-40,8.E-40, 
    9.E-40,1.E-39,1.E-30,2.E-30,3.E-30,4.E-30,5.E-30,6.E-30, 
    7.E-30,8.E-30,9.E-30,1.E-29,1.E-20,2.E-20,3.E-20,4.E-20, 
    5.E-20,6.E-20,7.E-20,8.E-20,9.E-20,1.E-19,1.E-10,2.E-10, 
    3.E-10,4.E-10,5.E-10,6.E-10,7.E-10,8.E-10,9.E-10,1.E-9,1.E-5, 
    2.E-5,3.E-5,4.E-5,5.E-5,6.E-5,7.E-5,8.E-5,9.E-5,1.E-4,2.E-4, 
    3.E-4,4.E-4,5.E-4,6.E-4,7.E-4,8.E-4,9.E-4,1.E-3,2.E-3,3.E-3, 
    4.E-3,5.E-3,6.E-3,7.E-3,8.E-3,9.E-3,1.E-2 };
  double em;
  int i;
  int nd;
  int nerror;
  double w;
  static double wm1[68] = {
           -1.000000000000000000023316439815971242034,
           -1.000000000000000000032974425414002562937,
           -1.000000000000000000040385258412884114431,
           -1.000000000000000000046632879631942484068,
           -1.000000000000000000052137144421794383842,
           -1.000000000000000000057113380167442850121,
           -1.000000000000000000061689501212464534966,
           -1.000000000000000000065948850828005125875,
           -1.000000000000000000069949319447913726103,
           -1.000000000000000000073733056744706376448,
           -1.000000000000002331643981597126015551422,
           -1.000000000000003297442541400259918073073,
           -1.000000000000004038525841288416879599233,
           -1.000000000000004663287963194255655478615,
           -1.00000000000000521371444217944744506897,
           -1.000000000000005711338016744295885146596,
           -1.000000000000006168950121246466181805002,
           -1.000000000000006594885082800527084897688,
           -1.000000000000006994931944791388919781579,
           -1.000000000000007373305674470655766501228,
           -1.000000000233164398177834299194683872234,
           -1.000000000329744254176269387087995047343,
           -1.00000000040385258418320678088280150237,
           -1.000000000466328796391912356113774800963,
           -1.000000000521371444308553232716574598644,
           -1.00000000057113380178315977436875260197,
           -1.000000000616895012251498501679602643872,
           -1.000000000659488508425026289634430354159,
           -1.000000000699493194642234170768892572882,
           -1.000000000737330567628282553087415117543,
           -1.000023316621036696460620295453277856456,
           -1.000032974787857057404928311684626421503,
           -1.000040385802079313048521250390482335902,
           -1.00004663360452259016530661221213359488,
           -1.0000521380505373899860247162705706318,
           -1.000057114467508637629346787348726350223,
           -1.000061690769779852545970707346938004879,
           -1.000065950300622136103491886720203687457,
           -1.00006995095046930174807034225078340539,
           -1.000073734868993836022551364404248563489,
           -1.007391489031309264813153180819941418531,
           -1.010463846806564696239430620915659099361,
           -1.012825626038880105597738761474228363542,
           -1.014819592594577564927398399257428492725,
           -1.016578512742400177512255407989807698099,
           -1.018170476517182636083407324035097024753,
           -1.019635932177973215702948823070039007361,
           -1.021001233780440980009663527189756124983,
           -1.022284686760270309618528459224732558767,
           -1.023499619082082348038906498637836105447,
           -1.033342436522109918536891072083243897233,
           -1.040939194524944844012076988438386306843,
           -1.047373634492196231421755878017895964061,
           -1.053065496629607111615572634090884988897,
           -1.058230030703619902820337106917657189605,
           -1.06299509412938704964298950857825124135,
           -1.067443986111355120560366087010834293872,
           -1.071634561663924136735470389832541413862,
           -1.07560894118662498941494486924522316597,
           -1.108081880631165502564629660944418191031,
           -1.133487001006868638317076487349933855181,
           -1.155245851821528613609784258821055266176,
           -1.174682608817289477552149783867901714817,
           -1.192475850408615960644596781702366026321,
           -1.209028378276581220769059281765172085749,
           -1.224602449817731587352403997390766826335,
           -1.239380103200799714836392811991400433357,
           -1.253493791367214516100457405907304877145};
  static double wm2[68] = {
           -96.67475603368003636615083422832414231073,
           -95.97433737593292677679699834708774152264,
           -95.56459382507349364043974513871359837914,
           -95.27386489130628866261760496192716897551,
           -95.0483515329550645558378163981346085731,
           -94.86408948075132603599669916724611501067,
           -94.70829516116125928735505687861553800851,
           -94.57333777268864473984718625104978190798,
           -94.45429521137271454134108055166168787618,
           -94.34780665137385269060032461028588648619,
           -73.37311031382297679706747875812087452918,
           -72.67033891766978907253811160121558649554,
           -72.25920015786413889986246462168541066725,
           -71.9674726772681844325410195162521230103,
           -71.74117979478106456261839111929684980709,
           -71.55627755942675731851469544735603279342,
           -71.39993966508440988906136771384270319452,
           -71.26450969134836299738230265916604879247,
           -71.14504894849287026061378869987876478469,
           -71.03818524971357411174259539994036186653,
           -49.96298427667447244531514297262540669957,
           -49.25557728489066973476436802404294348267,
           -48.84167348449764278180827692232244878061,
           -48.54795966722336777861228992424053274064,
           -48.32011181512544381639923088992262632623,
           -48.13392971864323755677656581326964166718,
           -47.97650308277095858785998266172487372203,
           -47.84012504158555569017852884133421231303,
           -47.71982419568730714141619502661365943996,
           -47.61220592218922310708330388890925734186,
           -26.29523881924692569411012882185491823773,
           -25.57429135222126159950976461862116397347,
           -25.15218334705420805339928870686463192335,
           -24.85251554543232259250342343156454440592,
           -24.61997095867949438248843689371454503831,
           -24.42989922074834124324823589226341161866,
           -24.26914663885402405126372567664280388966,
           -24.12985944288624210229238972590881794092,
           -24.00697058168597098928369714836882130512,
           -23.8970195845316574350263109196222825525,
           -14.16360081581018300910955630361089957762,
           -13.41624453595298662833544556875899262976,
           -12.97753279184081358418630625949303360266,
           -12.66551396826200331850774017793451747947,
           -12.42304039760186078066171146072124458063,
           -12.22461776385387453853455424320739669321,
           -12.05663003490708840623665404674007291018,
           -11.91094134143842011964821167497982287763,
           -11.78229922740701885487699061601349928173,
           -11.66711453256635441837882744697047370583,
           -10.90655739570090676132157335673785028979,
           -10.45921112040100393534625826514848865968,
           -10.14059243262036578763968437893562720385,
           -9.892699522704254067620287857665824159861,
           -9.689637966382397752838283301312347921626,
           -9.517569762038614935107630230444563521109,
           -9.368222172408836799233763466046500781388,
           -9.236251966692597369166416348621131600216,
           -9.11800647040274012125833718204681427427,
           -8.335081377982507150789361715143483020265,
           -7.872521380098708883395239767904984410792,
           -7.541940416432904084217222998374802941589,
           -7.283997135099081646930521042317118095276,
           -7.072162048994701667487346245044653243434,
           -6.892241486671583156187212318718730022068,
           -6.735741661607793269808533725369490789074,
           -6.597171733627119347342347717832724288261,
           -6.472775124394004694741057892724488037104};
  static double wp1[68] = {
           -.9999999999999999999766835601840287579665,
           -.9999999999999999999670255745859974370634,
           -.9999999999999999999596147415871158855702,
           -.9999999999999999999533671203680575159335,
           -.9999999999999999999478628555782056161596,
           -.9999999999999999999428866198325571498809,
           -.9999999999999999999383104987875354650364,
           -.9999999999999999999340511491719948741275,
           -.9999999999999999999300506805520862739007,
           -.9999999999999999999262669432552936235556,
           -.9999999999999976683560184028776088243496,
           -.9999999999999967025574585997473306784697,
           -.9999999999999959614741587115939935280812,
           -.9999999999999953367120368057588420244704,
           -.9999999999999947862855578205706768098859,
           -.9999999999999942886619832557258611080314,
           -.9999999999999938310498787535591888253966,
           -.999999999999993405114917199501910108482,
           -.9999999999999930050680552086436996003626,
           -.9999999999999926266943255293804772564852,
           -.9999999997668356018584094585181033975713,
           -.9999999996702557458962181283375794922681,
           -.9999999995961474159255244922555603070484,
           -.9999999995336712037530626747373742782638,
           -.9999999994786285558726655558473617503914,
           -.9999999994288661984343027719079710168757,
           -.9999999993831049880022078023099082447845,
           -.9999999993405114918649237720678678043098,
           -.9999999993005068056839596486461928553989,
           -.9999999992626694327341550240404575805522,
           -.9999766837414008807143234266407434345965,
           -.9999670259370180970391011806287847685011,
           -.9999596152852334187587360603177913882165,
           -.9999533678452277190993205651165793258207,
           -.9999478637616504968301143759542621752943,
           -.9999428877071168268324462680980110604599,
           -.999938311767283189655618359697592754013,
           -.999934052598878483932035240348113191731,
           -.9999300523114688962155368933174163936848,
           -.9999262687553819399632780281900349826094,
           -.9926447551971221136721993073029112268763,
           -.9896086425917686478635208903220735023288,
           -.9872831094708759013315476674998231771112,
           -.9853253899681719161468126266199947992874,
           -.9836027178149637071691226667555243369797,
           -.9820470029764667038452666345865058694192,
           -.9806177971936827573257045283891513709368,
           -.97928874641099293421931043027104578327,
           -.9780415451927629881943028498821429186059,
           -.9768628655744219140604871252425961901255,
           -.967382626983074241885253344632666448927,
           -.9601485420712594199373375259293860324633,
           -.9540768694875733222057908617314370634111,
           -.9487478690765183543410579996573536771348,
           -.9439462911219380338176477772712853402016,
           -.9395442782590063946376623684916441100361,
           -.9354585313336439336066341889767099608018,
           -.9316311953818583253420613278986500351794,
           -.9280201500545670487600430252549212247489,
           -.8991857663963733198571950343133631348347,
           -.8774287170665477623395641312875506084256,
           -.8593275036837387237312746018678000939451,
           -.8435580020488052057849697812109882706542,
           -.8294416857114015557682843481727604063558,
           -.8165758053803078481644781849709953302847,
           -.8046981564792468915744561969751509934994,
           -.7936267540949175059651534957734689407879,
           -.7832291989812967764330746819464532478021};
  static double wp2[40] = {
           9.999999990000000014999999973333333385417E-10, 
           1.9999999960000000119999999573333335E-9, 
           2.999999991000000040499999784000001265625E-9, 
           3.999999984000000095999999317333338666667E-9, 
           4.999999975000000187499998333333349609375E-9, 
           5.999999964000000323999996544000040499999E-9, 
           6.99999995100000051449999359733342086979E-9, 
           7.999999936000000767999989077333503999997E-9, 
           8.999999919000001093499982504000307546869E-9, 
           9.999999900000001499999973333333854166656E-9,
           9.901473843595011885336326816570107953628E-3, 
           1.961158933740562729168248268298370977812E-2, 
           2.913845916787001265458568152535395243296E-2, 
           3.848966594197856933287598180923987047561E-2, 
           4.767230860012937472638890051416087074706E-2, 
           5.669304377414432493107872588796066666126E-2, 
           6.555812274442272075701853672870305774479E-2, 
           7.427342455278083997072135190143718509109E-2, 
           8.284448574644162210327285639805993759142E-2, 
           9.127652716086226429989572142317956865312E-2,
           -1.000000001000000001500000002666666671875E-9, 
           -2.000000004000000012000000042666666833333E-9, 
           -3.000000009000000040500000216000001265625E-9, 
           -4.000000016000000096000000682666672E-9, 
           -5.000000025000000187500001666666682942709E-9, 
           -6.000000036000000324000003456000040500001E-9, 
           -7.000000049000000514500006402666754203126E-9, 
           -8.000000064000000768000010922666837333336E-9, 
           -9.000000081000001093500017496000307546881E-9, 
           -1.000000010000000150000002666666718750001E-8,
           -1.010152719853875327292018767138623973671E-2, 
           -2.041244405580766725973605390749548004159E-2, 
           -3.094279498284817939791038065611524917276E-2, 
           -4.170340843648447389872733812553976786256E-2, 
           -5.270598355154634795995650617915721289428E-2, 
           -6.396318935617251019529498180168867456393E-2, 
           -7.548877886579220591933915955796681153525E-2, 
           -8.729772086157992404091975866027313992649E-2, 
           -9.940635280454481474353567186786621057821E-2, 
           -1.118325591589629648335694568202658422726E-1};
  static double wp3[10] = {
           1.745528002740699383074301264875389911535,
           3.385630140290050184888244364529726867492,
           5.249602852401596227126056319697306282521,
           7.231846038093372706475618500141253883968,
           9.284571428622108983205132234759581939317,
           11.38335808614005262200015678158500428903,
           13.5143440103060912090067238511621580283,
           15.66899671545096218719628189389457073619,
           17.84172596742146918254060066535711011039,
           20.02868541330495078123430607181488729749};
  static double x2[20] = {
    1.E-9,2.E-9,3.E-9,4.E-9,5.E-9,6.E-9,7.E-9,8.E-9,9.E-9,1.E-8, 
    1.E-2,2.E-2,3.E-2,4.E-2,5.E-2,6.E-2,7.E-2,8.E-2,9.E-2,1.E-1};
  static double x3[10] = {
    1.E1,1.E2,1.E3,1.E4,1.E5,1.E6,1.E7,1.E8,1.E9,1.E10};
//
//  Compare the approximations of WAPR with the given exact values.
//
  cout << "\n";
  cout << "TEST01\n";
  cout << "  Compare WAPR(X) to stored values.\n";
//
//  Wp results for x near -exp(-1).
//
  cout << "\n";
  cout << "  Wp results for x near -exp(-1)\n";
  cout << "\n";
  cout << "   Offset x    W(x) (WAPR)";
  cout << "   W(x) (EXACT)   Digits Correct\n";
  cout << "\n";

  for ( i = 0; i < 68; i++ )
  {
    if ( dx1[i] == 0.0 )
    {
      em = - exp ( -1.0 );
      w = wapr ( em, 0, nerror, 0 );
    }
    else
    {
      w = wapr ( dx1[i], 0, nerror, 1 );
    }

    if ( w == wp1[i] )
    {
      nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
    }
    else
    {
      nd = ( int ) ( log10 ( fabs ( wp1[i] / ( w - wp1[i] ))) + 0.5 );
    }
    cout << setprecision(8) << setw(17) << dx1[i]
         << setprecision(8) << setw(17) << w
         << setprecision(8) << setw(17) << wp1[i] << "      "
         << setw(3) << nd << "\n";
  }
//
//  Wp results for x near 0.
//
  cout << "\n";
  cout << "  Wp results for x near 0\n";
  cout << "\n";
  cout << "      x    W(x) (WAPR)";
  cout << "     W(x) (EXACT)   Digits Correct\n";
  cout << "\n";

  for ( i = 0; i < 20; i++ )
  {
    w = wapr ( x2[i], 0, nerror, 0 );
    if ( w == wp2[i] )
    {
      nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
    }
    else
    {
      nd = ( int ) ( log10 ( fabs ( wp2[i] / ( w - wp2[i] ))) + 0.5 );
    }
    cout << setprecision(8) << setw(17) << x2[i]
         << setprecision(8) << setw(17) << w
         << setprecision(8) << setw(17) << wp2[i] << "      "
         << setw(3) << nd << "\n";
  }

  for ( i = 0; i < 20; i++ )
  {
    w = wapr ( -x2[i], 0, nerror, 0 );
    if ( w == wp2[20+i] )
    {
      nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
    }
    else
    {
      nd = ( int ) ( log10 ( fabs ( wp2[20+i] / ( w - wp2[20+i] ) ) ) + 0.5 );
    }
    cout << setprecision(8) << setw(17) << -x2[i]
         << setprecision(8) << setw(17) << w
         << setprecision(8) << setw(17) << wp2[20+i] << "      "
         << setw(3) << nd << "\n";
  }
//
//  Other Wp results.
//
  cout << "\n";
  cout << "  Other Wp results\n";
  cout << "\n";
  cout << "      x     W(x) (WAPR)";
  cout << "     W(x) (EXACT)   Digits Correct\n";
  cout << "\n";

  for ( i = 0; i < 10; i++ )
  {
    w = wapr ( x3[i], 0, nerror, 0 );
    if ( w == wp3[i] )
    {
      nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
    }
    else
    {
      nd = ( int ) ( log10 ( fabs ( wp3[i] / ( w - wp3[i] ))) + 0.5 );
    }
    cout << setprecision(8) << setw(17) << x3[i]
         << setprecision(8) << setw(17) << w
         << setprecision(8) << setw(17) << wp3[i] << "      "
         << setw(3) << nd << "\n";
  }
//
//  Wm results for x near -exp(-1).
//
  cout << "\n";
  cout << "  Wm results for x near 0\n";
  cout << "\n";
  cout << "      x    W(x) (WAPR)";
  cout << "     W(x) (EXACT)   Digits Correct\n";
  cout << "\n";

  for ( i = 0; i < 68; i++ )
  {
    w = wapr ( dx1[i], 1, nerror, 1 );
    if ( w == wm1[i] )
    {
      nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
    }
    else
    {
      nd = ( int ) ( log10 ( fabs ( wm1[i] / ( w - wm1[i] ))) + 0.5 );
    }
    cout << setprecision(8) << setw(17) << dx1[i]
         << setprecision(8) << setw(17) << w
         << setprecision(8) << setw(17) << wm1[i] << "      "
         << setw(3) << nd << "\n";
  }
//
//  Wm results for x near 0.
//  Check for underflow.
//
  cout << "\n";
  cout << "  Wm results for x near -exp(-1)\n";
  cout << "\n";
  cout << "   Offset x    W(x) (WAPR)";
  cout << "     W(x) (EXACT)   Digits Correct\n";
  cout << "\n";

  for ( i = 0; i < 68; i++ )
  {
    if ( 0.0 < dx1[i] )
    {
      w = wapr ( -dx1[i], 1, nerror, 0 );
      if ( w == wm2[i] )
      {
        nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
      }
      else
      {
        nd = ( int ) ( log10 ( fabs ( wm2[i] / ( w - wm2[i] ))) + 0.5 );
      }
      cout << setprecision(8) << setw(17) << -dx1[i]
           << setprecision(8) << setw(17) << w
           << setprecision(8) << setw(17) << wm2[i] << "      "
           << setw(3) << nd << "\n";
    }
  }
  return;
}
//****************************************************************************80

void test02 ( int nbits, double dx, int n )

//****************************************************************************80
//
//  Purpose:
//
//    TEST02 tests WAPR(X) when X is the offset of the argument from -exp(-1).
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    17 June 2014
//
//  Author:
//
//    Original FORTRAN77 version by Andrew Barry, S. J. Barry, 
//    Patricia Culligan-Hensley.
//    This C++ version by John Burkardt.
//
//  Parameters:
//
//    Input, int NBITS, the number of bits in the mantissa.
//
//    Input, double DX, the initial offset.
//
//    Input, int N, the number of offset arguments to generate.
//
{
  int i;
  int ifmt;
  int iw;
  int l;
  int nd;
  int ner;
  int nerror;
  double w;
  double we;
  double x;
  double xmax;
  double xmin;

  cout << "\n";
  cout << "TEST02\n";
  cout << "  Input X is the offset from -exp(-1).\n";

  l = 1;
  ifmt = 0;
  xmax = n * dx - exp ( -1.0 );
  xmin = 0.0;

  if ( xmax <= 0.0 )
  {
    iw = 1;
    cout << "  Both branches of the W function will be checked.\n";
  }
  else
  {
    iw = 0;
    cout << "  Wp has been selected (maximum x is > 0)\n";
  }

  cout << "\n";
  cout << "  Results for Wp(x):\n";

  if ( ifmt == 0 )
  {
    cout << "\n";
    cout << "   Offset x    W(x) (WAPR)";
    cout << "     W(x) (BISECT)  Digits Correct\n";
  }
  else
  {
    cout << "\n";
    cout << "     x     W(x) (WAPR)";
    cout << "     W(x) (BISECT)  Digits Correct\n";
  }

  cout << "\n";

  for ( i = 1; i <= n + 1; i++ )
  {
    x = xmin + i * dx;
    w = wapr ( x, 0, nerror, l );

    if ( nerror == 1 )
    {
      cout << "  The value of X = " << x << " is out of range.\n";
    }
    else
    {
      we = bisect ( x, 0, ner, l );

      if ( ner == 1 )
      {
        cout << "\n";
        cout << " BISECT did not converge for x = " << x << "\n";
        cout << "  Try reducing NBITS.\n";
      }

      if ( w == we )
      {
        nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
      }
      else
      {
        nd = ( int ) ( log10 ( fabs ( we / ( w - we ) ) ) + 0.5 );
      }
      cout << setprecision(8) << setw(17) << x
           << setprecision(8) << setw(17) << w
           << setprecision(8) << setw(17) << we << "      "
           << setw(3) << nd << "\n";
    }
  }

  if ( iw == 1 )
  {
    cout << "\n";
    cout << "  Results for Wm(x):\n";

    if ( ifmt == 0 )
    {
      cout << "\n";
      cout << "   Offset x    W(x) (WAPR)";
      cout << "     W(x) (BISECT)  Digits Correct\n";
    }
    else
    {
      cout << "\n";
      cout << "     x     W(x) (WAPR)";
      cout << "     W(x) (BISECT)  Digits Correct\n";
    }

    cout << "\n";

    for ( i = 1; i <= n + 1; i++ )
    {
      x = xmin + i * dx;
      w = wapr ( x, 1, nerror, l );

      if ( nerror == 1 )
      {
        cout << "  The value of X = " << x << " is out of range.\n";
      }
      else
      {
        we = bisect ( x, 1, ner, l );

        if ( ner == 1 )
        {
          cout << "\n";
          cout << " BISECT did not converge for x = " << x << "\n";
          cout << "  Try reducing NBITS.\n";
        }
  
        if ( w == we )
        {
          nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
        }
        else
        {
          nd = ( int ) ( log10 ( fabs ( we / ( w - we ) ) ) + 0.5 );
        }
        cout << setprecision(8) << setw(17) << x
             << setprecision(8) << setw(17) << w
             << setprecision(8) << setw(17) << we << "      "
             << setw(3) << nd << "\n";
      }
    }
  }

  return;
}
//****************************************************************************80

void test03 ( int nbits, double xmin, double xmax, int n )

//****************************************************************************80
//
//  Purpose:
//
//    TEST03 tests WAPR(X) when X is the argument.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    17 June 2014
//
//  Author:
//
//    Original FORTRAN77 version by Andrew Barry, S. J. Barry, 
//    Patricia Culligan-Hensley.
//    This C++ version by John Burkardt.
//
//  Parameters:
//
//    Input, int NBITS, the number of bits in the mantissa.
//
//    Input, double XMIN, XMAX, the range.
//
//    Input, int N, the number of equally spaced values
//    in the range at which arguments are to be chosen.
//
{
  double dx;
  int i;
  int ifmt;
  int iw;
  int l;
  int nd;
  int ner;
  int nerror;
  double temp;
  double w;
  double we;
  double x;

  cout << "\n";
  cout << "TEST03\n";
  cout << "  Input X is the argument.\n";

  l = 0;
  ifmt = 1;

  if ( xmax < xmin )
  {
    temp = xmin;
    xmin = xmax;
    xmax = temp;
  }

  dx = ( xmax - xmin ) / ( double ) ( n );
  xmin = xmin - dx;

  if ( xmax <= 0.0 )
  {
    iw = 1;
    cout << "  Both branches of the W function will be checked.\n";
  }
  else
  {
    iw = 0;
    cout << "  Wp has been selected (maximum x is > 0)\n";
  }

  cout << "\n";
  cout << "  Results for Wp(x):\n";

  if ( ifmt == 0 )
  {
    cout << "\n";
    cout << "   Offset x    W(x) (WAPR)";
    cout << "     W(x) (BISECT)  Digits Correct\n";
  }
  else
  {
    cout << "\n";
    cout << "     x     W(x) (WAPR)";
    cout << "     W(x) (BISECT)  Digits Correct\n";
  }
  cout << "\n";

  for ( i = 1; i <= n + 1; i++ )
  {
    x = xmin + i * dx;
    w = wapr ( x, 0, nerror, l );

    if ( nerror == 1 )
    {
      cout << "  The value of X = " << x << " is out of range.\n";
    }
    else
    {
      we = bisect ( x, 0, ner, l );

      if ( ner == 1 )
      {
        cout << "\n";
        cout << " BISECT did not converge for x = " << x << "\n";
        cout << "  Try reducing NBITS.\n";
      }

      if ( w == we )
      {
        nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
      }
      else
      {
        nd = ( int ) ( log10 ( fabs ( we / ( w - we ))) + 0.5 );
      }
      cout << setprecision(8) << setw(17) << x
           << setprecision(8) << setw(17) << w
           << setprecision(8) << setw(17) << we << "      "
           << setw(3) << nd << "\n";
    }
  }

  if ( iw == 1 )
  {
    cout << "\n";
    cout << "  Results for Wm(x):\n";

    if ( ifmt == 0 )
    {
      cout << "\n";
      cout << "   Offset x    W(x) (WAPR)";
      cout << "     W(x) (BISECT)  Digits Correct\n";
    }
    else
    {
      cout << "\n";
      cout << "     x     W(x) (WAPR)";
      cout << "     W(x) (BISECT)  Digits Correct\n";
    }

    for ( i = 1; i <= n + 1; i++ )
    {
      x = xmin + i * dx;
      w = wapr ( x, 1, nerror, l );

      if ( nerror == 1 )
      {
        cout << "  The value of X = " << x << " is out of range.\n";
      }
      else
      {
        we = bisect ( x, 1, ner, l );

        if ( ner == 1 )
        {
          cout << "\n";
          cout << " BISECT did not converge for x = " << x << "\n";
          cout << "  Try reducing NBITS.\n";
        }

        if ( w == we )
        {
          nd = ( int ) ( log10 ( pow ( 2.0, nbits ) ) + 0.5 );
        }
        else
        {
          nd = ( int ) ( log10 ( fabs ( we / ( w - we ))) + 0.5 );
        }
        cout << setprecision(8) << setw(17) << x
             << setprecision(8) << setw(17) << w
             << setprecision(8) << setw(17) << we << "      "
             << setw(3) << nd << "\n";
      }
    }
  }
  return;
}