Installing a loop for more efficient script

Good Morning,

I have a csv file with 305 lines. This lines shows the measured intensitiy of elements. I need to correct interferences between the elements. The elements are saved in a string, called element_RL and the intensities are saved as doubles in intens_RL.

Therefore I am searching the element:

[~, int_elem_RL] = ismember('54Fe+', element_RL);

Then I am saving its intensity:

intens_int(:,1)=intens_RL(:,int_elem_RL);

And in the following I calculate the interference and safe the new intensity:

intens_RL(:,63)=intens_int(:,1)-0.028.*intens_RL(:,58);

So I am doing this for a lot of elements and have to write around 200 lines. I wanted to ask if somebody knows how I could short this or make it more efficient, for example with a loop?

Here are more lines of my code:

[~, int_elem_RL] = ismember('54Fe+', element_RL); 
intens_int(:,1)=intens_RL(:,int_elem_RL);
intens_RL(:,63)=intens_int(:,1)-0.028.*intens_RL(:,58); 
[~, int_elem_RL] = ismember('58Fe+', element_RL); 
intens_int(:,1)=intens_RL(:,int_elem_RL);
intens_RL(:,70)=intens_int(:,1)-2.617.*intens_RL(:,73); 
[~, int_elem_RL] = ismember('58Ni+', element_RL); 
intens_int(:,1)=intens_RL(:,int_elem_RL);
intens_RL(:,71)=intens_int(:,1)-0.003.*intens_RL(:,66); 
[~, int_elem_RL] = ismember('64Zn+', element_RL); 
intens_int(:,1)=intens_RL(:,int_elem_RL);
intens_RL(:,78)=intens_int(:,1)-0.035.*intens_RL(:,73);

My probleme is, that I dont know how to install a loop, because the lines are so individual.

Maybe somebody else has an idea. I would appreciate this.

[Rik]

How do you determine the value to subtract and the indices to use?

[Tatjana Mü]

The value to subtract is manually calculated. If I understand correctly, you mean the indices in the last row? For example for the explained line: 63 is the column where 54Fe is in the original file and 58 is the column of an element, which you use for correction.

[Mathieu NOE]

hello

maybe it would be a good idea to share the CSV file as well

all the best

Answer 1

[Rik]

If there is no way to determine these values, you will have to hard-code them somewhere. So you might as well do it in a cell array:

indices={...
    '54Fe+',63,-0.028,58;
    '58Fe+',70,-2.617,73;
    '58Ni+',71,-0.003,66;
    '64Zn+',78,-0.035,73};
for n=1:size(indices,1)
    [~, int_elem_RL] = ismember(indices{n,1}, element_RL); 
    intens_int(:,1)=intens_RL(:,int_elem_RL);
    intens_RL(:,indices{n,2})=intens_int(:,1)+indices{n,3}.*intens_RL(:,indices{n,4});
end