#
memory

**memory**,
a MATLAB code which
declares and uses a sequence of larger and larger arrays,
to see what the memory limits are on a given computer.

The program tries an increasing series of values of **N**, using
powers of 2, between limits that you set. At some point, the program
may ask for more memory than can be provided, and crash. This is one
way to find out what the memory ceiling is! The relevant power of 2
is likely to be in the 20's:

Log(N) | N |

20 | 1,048,576 |

21 | 2,097,152 |

22 | 4,194,304 |

23 | 8,388,608 |

24 | 16,777,216 |

25 | 33,554,432 |

26 | 67,108,864 |

27 | 134,217,728 |

28 | 268,435,456 |

29 | 536,870,912 |

30 | 1,073,741,824 |

Remember that your memory is probably described in terms of bytes,
but that integers and reals require 4 bytes, and double precision reals
require 8 bytes.

###
Usage:

**memory** ( *log_n_min*, *log_n_max* )

runs the program for sizes **N** = 2^{log_n_min} to
2^{log_n_max}.
###
Licensing:

The computer code and data files described and made available on this web page
are distributed under
the GNU LGPL license.

###
Languages:

**memory** is available in
a C version and
a C++ version and
a FORTRAN90 version and
a MATLAB version.

###
Related Data and Programs:

linpack_bench,
a MATLAB code which
measures the time needed to factor and solve a linear system.

machine,
a MATLAB code which
can return various machine constants.

memory_test

timer_test,
a MATLAB code which
demonstrates how to compute CPU time or elapsed time.

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Source Code:

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Last revised on 24 November 2020.
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