Running csv file through if else statement
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My aim is to have code that will run a csv file through an if statement. I have got it to extract the correct information from the file
I have been using the following code:
fid = fopen('eyes.csv');
data = textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %*s','Delimiter',',','Headerlines',1);
fclose(fid);
numrows = size(data,1);
for rownum = 1:numrows
thisrow = data(rownum,:);
val1 = thisrow{1};
val2 = thisrow{2};
val3 = thisrow{3};
val4 = thisrow{4};
val5 = thisrow{5};
val7 = thisrow{7};
val8 = thisrow{8};
val10 = thisrow{10};
val11 = thisrow{11};
val12 = thisrow{12};
val13 = thisrow{13};
if val3<=3 && val10<=1.6 && val1<=56
outcome = 'F';
elseif val3<=3 && val10<=1.6 && val1>56 && val2<=0
outcome = 'F';
elseif val3<=3 && val10<=1.6 && val1>56 && val2>0 && val7<=1
outcome = 'F';
etc.
However I get the error:
Operands to the || and && operators must be convertible to logical scalar values.
Error in Untitled (line 18)
if val3<=3 && val10<=1.6 && val1<=56
I don't understand becuase all the data for each variable 3, 1.4, 67 etc. When I change && to &, it only provides me with one result instead of giving me answers to all the cases in the file.
Any advice? Thanks
回答（1 个）
Star Strider
2018-11-14
0 个投票
First, if you are comparing vectors,use one ‘&’, not ‘&&’.
Second, again if you are comparing vectors, you will likely need the any or the related all function, depending on what you are doing.
5 个评论
Star Strider
2018-11-14
It seems to me that from the way you imported your file, you are comparing vectors, since each ‘val#’ vector is a row of your ‘data’ matrix.
Your code is doing something like this:
val1 = rand(1,10)
val2 = rand(1,10)
test1 = val1 < 0.7
test2 = val2 > 0.3
logical_compare = (val1 < 0.7) & (val2 > 0.3)
that evaluated will produce for example:
val1 =
0.6557 0.0357 0.8491 0.9340 0.6787 0.7577 0.7431 0.3922 0.6555 0.1712
val2 =
0.7060 0.0318 0.2769 0.0462 0.0971 0.8235 0.6948 0.3171 0.9502 0.0344
test1 =
1×10 logical array
1 1 0 0 1 0 0 1 1 1
test2 =
1×10 logical array
1 0 0 0 0 1 1 1 1 0
logical_compare =
1×10 logical array
1 0 0 0 0 0 0 1 1 0
Yolu need to examine the results of the expressions you are evaluating so you can be certain your code is doing what you want it to.
Star Strider
2018-11-14
I cannot accurately reproduce the problem you are having without your file.
When I emulate it (as best I can otherwise), you actually are comparing vectors, so you need to decide how you want to do it.
Example —
data = num2cell(randi(9,10));
numrows = size(data,1);
for rownum = 1:numrows
thisrow = data(rownum,:);
val1 = thisrow{1};
val2 = thisrow{2};
L(rownum) = (val1 < 5) & (val2 > 5);
end
all_v = all(L)
any_v = any(L)
Peggatha
2018-11-14
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