How to evaluate function matrix in for loop

The text file is 8 X178

First four column are the y axis values do not change

last 4 rows are the x values and im converting them in a function Wavelength

I am having an issue with my function. I am trying to pass my function a 4X178 matrix and evaluate is at each point for each row and save it into another row vector.

Text file provided

clc
clear

type TestPatient.txt
PI = dlmread('TestPatient.txt');

[n,m] = size(PI); 
PW = [PI(5,:); PI(6,:); PI(7,:); PI(8,:)];

DarkWave = ones(4,m);
AmbientWave = ones(4,m); SunWave = ones(4,m); PatientWave = ones(4,m); 
        
    for i = 1:4
        % dark
        %DarkWave(i) = Wavelength(D1(i,m), 4,m);
        % ambient light
        %AmbientWave(i) = Wavelength(A1(i,m), 4,m);
        % sun light 
        %SunWave(i) = Wavelength (SN1(i,m),4,m); 
        %Patient Data
        PatientWave(i) = Wavelength (PW(i),4,m);
    end %end for loop 



%Patient Plot 
subplot(2,2,4) 
plot(PI(1,:), PatientWave(1), 'b',PI(2,:), PatientWave(2), 'r',PI(3,:), PatientWave(3), 'g',PI(4,:), PatientWave(4), 'k')
title('Patient Readings')
legend('White Lights', 'IR Lights', 'Near IR Lights', 'UV Lights') 
xlabel('Wavelength')
ylabel('Intensity')

%%
function f  = Wavelength(x, n,m)
%n = size of rows
%m = number of columns 
A0 = 3.137749190*10^2;
B1 = 2.712866004; 
B2 = -1.458600858*10^-3; 
B3 = -4.854192924*10^-6; 
B4 = -1.392291111*10^-9; 
B5 = 1.937582620*10^-11; 
%x = pixel data
WL = [n,m] ;
for i  = 1: n
    % for loop  for column 
    for j = 1: m 
            % for loop for rows 
        %WL = wavelengh conversion of pixels to Wavelength 
        WL(i) = A0 + (B1*x(i,j))+ (B2*x(i,j)^2) + (B3*x(i,j)^3)+(B4*x(i,j)^4) + (B5*x(i,j)^5); 
    end % end for loop
end % end for loop 
f= WL; 
end % end of function 

[Walter Roberson]

You assign to WL(i) within a for j loop. The value calculated for j = 2 will overwrite the value calculated for j = 1, the j = 3 will overwrite the value calculated when j = 2, and so on.

[Alexa Shumaker]

I was trying to store the conversion in WL(i) for each iteration but is that wrong and I don't know how to fix it because i want to convert the last 4 rows of the text file and i want to pass the row and its conversions within each column

[Alexa Shumaker]

Now i am getting this error Index in position 2 exceeds array

bounds (must not exceed 1).

What does that mean?

function f  = Wavelength(x,n,m)
%n = size of rows
%m = number of columns 
A0 = 3.137749190*10^2;
B1 = 2.712866004; 
B2 = -1.458600858*10^-3; 
B3 = -4.854192924*10^-6; 
B4 = -1.392291111*10^-9; 
B5 = 1.937582620*10^-11; 
%x = pixel data
WL = [n,m] ;

    % for loop  for column 
    for j = 1: m 
            % for loop for rows 
        %WL = wavelengh conversion of pixels to Wavelength 
        WL(n,j) = A0 + (B1*x(n,j))+ (B2*x(n,j)^2) + (B3*x(n,j)^3)+(B4*x(n,j)^4) + (B5*x(n,j)^5); 
    end % end for loop 
f= WL; 
end % end of function 

Answer 1

[Walter Roberson]

function f  = Wavelength(x)
A0 = 3.137749190*10^2;
B1 = 2.712866004; 
B2 = -1.458600858*10^-3; 
B3 = -4.854192924*10^-6; 
B4 = -1.392291111*10^-9; 
B5 = 1.937582620*10^-11;
P = [B5 B4 B3 B2 B1 A0];
f= polyval(P, x); 
end % end of function