Gnuplot: How to load and display single numeric value from data file

Question

My data file has this content

# data file for use with gnuplot
# Report 001
# Data as of Tuesday 03-Sep-2013 
total   1976
case1   522 278 146 65  26  7
case         


        

Answer 1

For linux and similar.

If you don't know the row number where your data is located, but you know it is in the n-th column of a row where the value of the m-th column is x, you can define a function

get_data(m,x,n,filename)=system('awk "\$'.m.'==\"'.x.'\"{print \$'.n.'}" '.filename)

and then use it, for example, as

y = get_data(1,"case2",4,"datafile.txt")

using data provided by user424855

print y

should return 15