function toms743_test01 ( nbits )

%*****************************************************************************80
%
%% toms743_test01() compares wapr() to stored values.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    15 June 2014
%
%  Author:
%
%    Original FORTRAN77 version by Andrew Barry, S. J. Barry, 
%    Patricia Culligan-Hensley.
%    This MATLAB version by John Burkardt.
%
%  Input:
%
%    integer NBITS, the number of bits in the mantissa.
%

%
%  Exact results for Wp(x).
%
%  X close to -exp(-1).
%
  dx1 = [ ...
           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 ];
  wp1(1:68) = [ ...
           -.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];
%
%  x close to 0.
%
  x2 = [ ...
           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];
  wp2(1:40) = [ ...
           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];
%
%  Other Wp results.
%
  x3 = [1.E+01,1.E+02,1.E+03,1.E+04,1.E+05,1.E+06,1.E+07,1.E+08,1.E+09,1.E+10];
  wp3 = [ ...
           1.745528002740699383074301264875389911535, ...
           3.385630140290050184888244364529726867492, ...
           5.249602852401596227126056319697306282521, ...
           7.231846038093372706475618500141253883968, ...
           9.284571428622108983205132234759581939317, ...
           11.38335808614005262200015678158500428903, ...
           13.5143440103060912090067238511621580283, ...
           15.66899671545096218719628189389457073619, ...
           17.84172596742146918254060066535711011039, ...
           20.02868541330495078123430607181488729749];
%
%  Exact results for Wm(x).
%
%  X close to -exp(-1).
%
  wm1(1:68) = [ ...
           -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];
%
%  X close to 0
%
  wm2(1:68) = [ ...
           -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];
%
%  Compare the approximations of WAPR with the given exact values.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'toms743_test01()\n' );
  fprintf ( 1, '  Compare wapr() to stored values.\n' );
%
%  Wp results for x near -exp(-1).
%
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Wp results for x near -exp(-1)\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '   Offset x    W(x) (WAPR)' );
  fprintf ( 1, '     W(x) (EXACT)   Digits Correct\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 68

    if ( dx1(i) == 0.0 )
      em = - exp ( -1.0 );
      [ w, nerror ] = wapr ( em, 0, 0 );
    else
      [ w, nerror ] = wapr ( dx1(i), 0, 1 );
    end

    if ( w == wp1(i) )
      nd = floor ( log10 ( 2.0 ^ nbits ) + 0.5 );
    else
      nd = floor ( log10 ( abs ( wp1(i) / ( w - wp1(i) ))) + 0.5 );
    end

    fprintf ( 1, '%17.8g      %17.8g      %17.8g      %3d\n',  dx1(i), w, wp1(i), nd );

  end
%
%  Wp results for x near 0.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Wp results for x near 0\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '      x    W(x) (WAPR)' );
  fprintf ( 1, '     W(x) (EXACT)   Digits Correct\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 20
    [ w, nerror ] = wapr ( x2(i), 0, 0 );
    if ( w == wp2(i) )
      nd = floor ( log10 ( 2.0 ^ nbits ) + 0.5 );
    else
      nd = floor ( log10 ( abs ( wp2(i) / ( w - wp2(i) ))) + 0.5 );
    end
    fprintf ( 1, '%17.8g      %17.8g      %17.8g      %3d\n', x2(i), w, wp2(i), nd );
  end

  for i = 1 : 20
    [ w, nerror ] = wapr ( -x2(i), 0, 0 );
    if ( w == wp2(20+i) )
      nd = floor ( log10 ( 2.0 ^ nbits ) + 0.5 );
    else
      nd = floor ( log10 ( abs ( wp2(20+i) / ( w - wp2(20+i) ) ) ) + 0.5 );
    end
    fprintf ( 1, '%17.8g      %17.8g      %17.8g      %3d\n',  -x2(i), w, wp2(20+i), nd );
  end
%
%  Other Wp results.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Other Wp results\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '      x     W(x) (WAPR)' );
  fprintf ( 1, '     W(x) (EXACT)   Digits Correct\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 10
    [ w, nerror ] = wapr ( x3(i), 0, 0 );
    if ( w == wp3(i) )
      nd = floor ( log10 ( 2.0 ^ nbits ) + 0.5 );
    else
      nd = floor ( log10 ( abs ( wp3(i) / ( w - wp3(i) ))) + 0.5 );
    end
    fprintf ( 1, '%17.8g      %17.8g      %17.8g      %3d\n',  x3(i), w, wp3(i), nd );
  end
%
%  Wm results for x near -exp(-1).
%
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Wm results for x near 0\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '      x    W(x) (WAPR)' );
  fprintf ( 1, '     W(x) (EXACT)   Digits Correct\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 68
    [ w, nerror ] = wapr ( dx1(i), 1, 1 );
    if ( w == wm1(i) )
      nd = floor ( log10 ( 2.0 ^ nbits ) + 0.5 );
    else
      nd = floor ( log10 ( abs ( wm1(i) / ( w - wm1(i) ))) + 0.5 );
    end
    fprintf ( 1, '%17.8g      %17.8g      %17.8g      %3d\n',  dx1(i), w, wm1(i), nd );
  end
%
%  Wm results for x near 0.
%  Check for underflow.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Wm results for x near -exp(-1)\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '   Offset x    W(x) (WAPR)' );
  fprintf ( 1, '     W(x) (EXACT)   Digits Correct\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 68

    if ( 0.0 < dx1(i) )
      [ w, nerror ] = wapr ( -dx1(i), 1, 0 );
      if ( w == wm2(i) ) 
        nd = floor ( log10 ( 2.0 ^ nbits ) + 0.5 );
      else
        nd = floor ( log10 ( abs ( wm2(i) / ( w - wm2(i) ))) + 0.5 );
      end
      fprintf ( 1, '%17.8g      %17.8g      %17.8g      %3d\n',  -dx1(i), w, wm2(i), nd );
    end

  end

  return
end
