read_dbl_from_file - Reads a double from a file
Example compile flags (system dependent):
-DLINUX_X86_64 -DLINUX_X86_64_OPTERON -DGNU_COMPILER
-lKJB -lfftw3 -lgsl -lgslcblas -ljpeg -lSVM -lstdc++ -lpthread -lSLATEC -lg2c -lacml -lacml_mv -lblas -lg2c -lncursesw
const char *file_name
This routine reads an double from a file. The file should have exactly one
double in it other than white space and comment lines. The value of the
double pointed to by dbl_ptr is only changed if the routine is succeeds.
ERROR on error, with an error message being set, otherwise NO_ERROR.
Failures inlude the file does not exist, cannot be opened for reading, and
does not have exactly one valid double other than white space and
This routine and read_double() are somewhat redundant. Currently, this
routine insists that there is exactly one number in the file, but
read_double() does not.
This software is not adequatedly tested. It is recomended that
results are checked independantly where appropriate.