Error in If-expression

I've made a for-loop for 5 subjects. I've got 2 datafiles. One being 'data_stair_rise' and one being 'data_sts'. Data_stair_rise contains 5 measurements, but data_sts contains only 4 measurements. So when the program goes through the for-loop, it will give an error as soon as the fifth measurement begins for the data_sts-file. So I created an if-expression saying that if the test-value becomes greater than 4, the program should break. But it gives an error that 'RASI' becomes empty when i_testen = 4.

aantal_pp = length(data_stair_rise)
for welke_pp=1:aantal_pp
  switch welke_pp
      case 1
      case 2
      case 3
      case 4
      case 5     
  end  
for i_testen=1:length(data_stair_rise)
RANK = data_stair_rise(welke_pp,i_testen).VideoSignals(:, strcmp('RANK', data_stair_rise(welke_pp, i_testen).VideoSignals_headers))
if i_testen <= 4
RASI = data_sts(welke_pp,i_testen).VideoSignals(:, strcmp('RASI', data_sts(welke_pp,i_testen).VideoSignals_headers));
XY(2,1) = max(RASI)
XY(1,1) = 0;
Begin_Eind_sts.Begin(i_testen) = abs(XY(2,2));
Begin_Eind_sts.Eind(i_testen) = abs(XY(1,2));
close all
elseif i_testen > 4
  break
end

Answer 1

[Star Strider]

I cannot follow what you are doing, but if you do not need to use the 5th value of ‘data_stair_rise’, simply subtract 1 from the length calculation:

length(data_stair_rise)-1

wherever you use it.

[Sam]

I got 2 datafiles. Data_stair_rise is a 5x5 and each cell is a struct. Within this struct there is a datafile that I use (there are also other files in the struct like columnheaders, etc.) But the problem is I have created a for-loop for 5subjectsx5measurements, and sometimes a subject is only measured 4 times. So the fifth cell in the struct is actually empty. But the program still calculates it, which gives an error because the cell is 'empty'.

[Image Analyst]

Yeah, longer code with bad indenting and no comments makes the code hard to follow. You can type control-a control-i to have MATLAB fix your indenting. Of course comments have to be manually typed in.

[Star Strider]

I certainly agree with I A on the necessity for readable code!

It would seem that you will have to test for the size of the data you are processing in your loop and make appropriate adjustments to the iteration limits. I have no idea how your data are organised, so my only suggestion is to create an outer loop that reads each subject, determines the size, and adjusts the inner loop index limits accordingly.