Introduction

It provides some utility subroutines and functions.

Type

subroutines

Source

src/s_util.f90

Usage

(1) C-like assertion.

subroutine s_assert(condition)
subroutine s_assert2(condition, message)

where condition is the logical condition that we have to assert, message is the additional message.

(2) Sort algorithm.

subroutine s_sorter1_i(nsize, list)
subroutine s_sorter1_d(nsize, list)
subroutine s_sorter2_i(nsize, list, indx)
subroutine s_sorter2_d(nsize, list, indx)
subroutine s_qsorter(nsize, list)
subroutine s_qscorer(pstart, pend, nsize, list)

The s_sorter1() and s_sorter2() subroutines implement the bubble algorithm, and the s_qsorter() subroutine implements the quick sort algorithm. The s_qscorer() subroutine is called by the s_qsorter() internally. DO NOT call it directly!

Here, nsize is size of the list, list is the dataset to be sorted. In s_sorter2(), the index of the dataset (indx) is also sorted.

(3) Combination algrbra.

subroutine s_combination(ntiny, nlarg, value)

     ! the small number
     integer, intent(in)  :: ntiny

     ! the large number
     integer, intent(in)  :: nlarg

     ! result value of the combination algebra
     integer, intent(out) :: value

It calculates combination algebra.

(4) String manipulation.

subroutine s_str_upcase(s)
subroutine s_str_lowcase(s)

     ! input/output string
     character(len=*), intent(inout) :: s

They are used to convert the input string s to upcase or lowcase.

subroutine s_str_count(string, substr, count)

     ! string to be examined
     character(len=*), intent(in) :: string

     ! substring in question
     character(len=*), intent(in) :: substr

     ! return value, number of occurrences
     integer, intent(out) :: count

It return the number of times a substring occurs.

subroutine s_str_compress(string)

     ! character string to be compressed.
     character(len=*), intent(inout) :: string

It return a copy of an input string with all whitespace (spaces and tabs) is removed.

(5) Date time manipulation.

subroutine s_time_builder(date_time_string)

     ! output date and time
     character(len=20), intent(out) :: date_time_string

It returns a string containing date and time in human readable format.

subroutine s_time_analyzer(time_iter, time_niter)

     ! time used in this iteration
     real(dp), intent(in) :: time_iter

     ! time used in total iteration
     real(dp), intent(in) :: time_niter

It is used to print the iteration timing information about continuous time quantum Monte Carlo quantum impurity solver.