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

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Martin Matisoff
Martin Matisoff 2017-4-6
编辑： Walter Roberson 2017-4-6
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]
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

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回答（2 个）

Walter Roberson
Walter Roberson 2017-4-6
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.
  2 个评论
Martin Matisoff
Martin Matisoff 2017-4-6
编辑：Walter Roberson 2017-4-6
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);

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Jan
Jan 2017-4-6
编辑：Jan 2017-4-6
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);
  1 个评论
Martin Matisoff
Martin Matisoff 2017-4-6
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.

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