Re: [Gnuplot-info] for loop iterating functions

[Thomas S. <t.s...@fz...>]

stibala <adam.stibal <at> gmail.com> writes:

> 
> Hello, 
> I have a matrix data set, each column contains a curve and I have a function
> fitted to each curve.
> I need to plot the original curves minus the respective fitted function and
> here comes the problem.
> My wanted code with for loop is
>  p for [i=2:11] "data.txt"  u 1:(column(i) - function>i<($1))
> so I can't imagine how to iterate through my functions numbered as the
> corresponding columns in data.
> It can be done without the loop simply
> p "data.txt" u 1:($2 - function2($1)), "data.txt" u 1:($3 - function3($1)),
> ...
> but I would like to plot it within the loop because I have a lot of data.
> All the functions are the same, but with different constants, for example
> g2(x)=exp(a2*x+b2)+c2 and g3(x)=exp(a3*x+b3)+c3.
> 
> Thank you for your help
> 
> Adam Stíbal
> 
> --

pass the loop variable as a second argument to the
function and distinguish between the different loop
steps using the ternary operator:
(here: from 2 to 5)

g(x,column)=\
 column==2?exp(a2*x+b2)+c2:\
  column==3?exp(a3*x+b3)+c3:\
   column==4?exp(a4*x+b4)+c4:\
    column==5?exp(a5*x+b5)+c5:\
     0/0