How do I change variable names without getting matrix dimension error?

The following code works as is, but when I try to rename the variables, e.g., s -> Ra, t -> Rs u -> RH, etc. I get an "exceeds matrix dimensions" error. My changed code is listed after the "This Works" area. The section I show as "Problem area" is when the errors occur. I have shown the changed code after the following code (shown below "&&&&&&&&" line). I hope this makes sense.

****************THIS WORKS ****************

filename = 'E:\My Documents\Maheteme\Sample Programs\BiometDataSetTestData_2a.csv';
delimiter = ',';
startRow = 2; %assign startRow to 'Q', first line of data

formatSpec = '%f%f%f%f%f%f%f%f%f%s%s%f%[^\n\r]';

fileID = fopen(filename,'r');

dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'EmptyValue' ,NaN,'HeaderLines' ,startRow-1, 'ReturnOnError', false, 'EndOfLine', '\r\n');

fclose(fileID);

d = dataArray{:, 1}; %DOY
Ra = dataArray{:, 2};
Rs = dataArray{:, 3};
RH = dataArray{:, 4};
Rn = dataArray{:, 5};
G = dataArray{:, 6};
Ta = dataArray{:, 7};
Ts = dataArray{:, 8};
U2 = dataArray{:, 9};

clearvars filename delimiter startRow formatSpec fileID dataArray ans;

headerlines = 1;
start_string = '260';
file_name = 'E:\My Documents\Maheteme\Sample Programs\BiometDataSetTestData_2.csv';

fileID = fopen(file_name);
line_no = 1;

n = 118; %Total number of rows 
Ra = 0;  %Rain
Rs = 0;  %Rs
RH = 0;  %RH
Rn = 0;  %Rn
G = 0;  %G
Ta = 0;  %Ta
Ts = 0;  %Ts
U2 = 0;  %Wind

while feof(fileID) == 0 
tline{line_no} = fgetl(fileID);
line_no = line_no+1;
end

index = strmatch(start_string,tline(headerlines+1:length(tline)))+headerlines;
S = tline{index(end)}
C = textscan (S, '%f %f %f %f %f %f %f %f %f %f %f');

index = index([end]);
n = index-1;

for i = 1:n %Sum of each column
    Ra = Ra + Ra(i);
    Rs = Rs + Rs(i);
    RH = RH + RH(i);
    Rn = Rn + Rn(i);
    G = G + G(i);
    Ta = Ta + Ta(i);
    Ts = Ts + Ts(i);
    U2 = U2 + U2(i);
end

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& MODIFIED CODE &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

d = dataArray{:, 1}; %DOY
Rain = dataArray{:, 2};
Rs = dataArray{:, 3};
RH = dataArray{:, 4};
Rn = dataArray{:, 5};
G = dataArray{:, 6};
Ta = dataArray{:, 7};
Ts = dataArray{:, 8};
U2 = dataArray{:, 9};

n = 118; %Total number of rows 
Ra = 0; %Rain
Rs = 0;  %Rs
RH = 0;  %RH
Rn = 0;  %Rn
G = 0;  %G
Ta = 0;  %Ta
Ts = 0;  %Ts
U2 = 0;  %Wind

---------------------------------Errors occurs here -------------------
Index exceeds matrix dimensions.

Error in LoadFileBiometDataCalculations_GOOD_CODE_PART1_rev_001 (line 113)
  Ra = Ra + Ra(i);
-----------------------------------------------------------------------

while feof(fileID) == 0 
tline{line_no} = fgetl(fileID);
line_no = line_no+1;
end

index = strmatch(start_string,tline(headerlines+1:length(tline)))+headerlines;
%S = tline{index(1)}
S = tline{index(end)}
C = textscan (S, '%f %f %f %f %f %f %f %f %f %f %f');
index = index([end]);
n = index-1;

for i = 1:n %Sum of each column
Ra = Ra + Rain(i);
Rs = Rs + Rs(i);
RH = RH + RH(i);
Rn = Rn + Rn(i);
G = G + G(i);
Ta = Ta + Ta(i);
Ts = Ts + Ts(i);
U2 = Wi + Wind(i);
end

disp(['    Rain    Rs    RH    Rn    G    Ta    Ts    Wind'])
[Ra    Rs    RH    Rn    G    Ta    Ts     U2

Ra_mean = Ra/n;
Rs_mean = Rs/n;
RH_mean = RH/n;
Rn_mean = Rn/n;
G_mean = G/n;
Ta_mean = Ta/n;
Ts_mean = Ts/n;
U2_mean = U2/n;

disp(['Ra_mean  Rs_mean RH_mean Rn_mean G_mean  Ta_mean Ts_mean U2_mean']) 
       [Ra_mean Rs_mean RH_mean Rn_mean G_mean  Ta_mean Ts_mean U2_mean]

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Answer 1

[Walter Roberson]

In the top section, you textscan into a variable and extract information from that variable.

d = dataArray{:, 1}; %DOY

and so on.

In the modified version, you

C = textscan (S, '%f %f %f %f %f %f %f %f %f %f %f');

and then do not use C.

[Martin Matisoff]

I think I muddied the water.

C = textscan is the same in both programs. I just forgot to include it in the modified program.

Here is my actual problem.

When I change the variable names from s, t, u etc. to their actual variable names, i.e., s=Ra, t=Rs, u=RH, v=Rn w=G x=Ta y=Ts and z=U2, I get an error when it reaches the FOR loop.

Here is what I have that works:

s = 0;  %Rain
t = 0;  %Rs
u = 0;  %RH
v = 0;  %Rn
w = 0;  %G
x = 0;  %Ta
y = 0;  %Ts
z = 0;  %Wind

for i = 1:n
    s = s + Rain(i)
    t = t + Rs(i);
    u = u + RH(i);
    v = v + Rn(i);
    w = w + G(i);
    x = x + Ta(i);
    y = y + Ts(i);
    z = z + Wind(i);
end

Here is the problematic code:

Ra = 0;  %Rain
Rs = 0;  %Rs
RH = 0;  %RH
Rn = 0;  %Rn
G = 0;  %G
Ta = 0;  %Ta
Ts = 0;  %Ts
U2 = 0;  %Wind

For i = 1:n
    Ra = Ra + Ra(i);
    Rs = Rs + Rs(i);
    RH = RH + RH(i);
    Rn = Rn + Rn(i);
    G = G + G(i);
    Ta = Ta + Ta(i);
    Ts = Ts + Ts(i);
    U2 = U2 + U2(i);

[Image Analyst]

Read http://www.mathworks.com/matlabcentral/answers/13205#answer_18099 and fix your post.

Answer 2

[Jan]

This must fail:

Rs = dataArray{:, 3};   % Rs is an array
Rs = 0;                 % Rs is overwritten by the scalar 0
for i = 1:n
  Rs = Rs + Rs(i);      % Works in the 1st iteration, but not for i=2
end

This should fail in the code marked as "THIS WORKS" also.

What should this loop produce? Do you want to calculate the sum? Then:

Rs     = dataArray{:, 3};
Rs_sum = sum(Rs);

[Martin Matisoff]

I am trying to calculate the sums based on date of year, i.e., sum all records where DOY = 260, then all records where DOY = 261, and then DOY = 262. I was using the FOR LOOP so that I could limit the sums to each DOY. Hope that makes sense.