if else statement

2012 4 11
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I have a for loop that used to open text files for plotting, and I want to have an if else statement that will set headerlines equal to 5 for test files having less than 500 rows, and headerlines equal to 400 for those having in excess of 500 rows. I have this so far but it does not seem to be working;
for k = 58:212
inputFileName = sprintf('MT_%05i-000.txt',k);
outputFileName = sprintf('results%05i.tiff',k);
fid = fopen(inputFileName);
newcmd=sprintf('more %s|wc -l', inputFileName);
[p,num_lines]=system(newcmd);
if num_lines<=500
datacell = textscan(fid, '%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f','HeaderLines',5);
fclose(fid);
else
datacell = textscan(fid, '%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f','HeaderLines',500);
fclose(fid); %number of %f reflects number of columns to record from text file
end

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Jan
Jan 2012-4-11
Please explain, what "does not seem to be working" means explicitely. It is hard to give an advice for an unknown problem, which appears in code, we cannot run. At first we do not have your data files, at second the effects of "system(newcmd)" are unknown.
douglas
douglas 2012-4-11
I'm not sure exactly, someone else wrote the if else statement I have for me, and I don't know what is wrong with it, I would be open to write a new one, but I'm not sure how to go about it. When I run the file it runs every plot with headerlines set to 5 and seems to ignore the if else statement completely
Thomas
Thomas 2012-4-11
@Jan, here is the question that went before it: http://www.mathworks.com/matlabcentral/answers/35073-for-loop-question-plot-figure
I suggested the newcmd if the user was on linux to count the num_lines
new_cmd=sprintf('more %s|wc -l', inputFileName);
[p,num_lines]=system(newcmd);
douglas
douglas 2012-4-11
oh your right you said it was for a linux based system, I'm using windows oops.
douglas
douglas 2012-4-11
it seems I didn't paste that in the question, but in my script it does have the command
newcmd=sprintf('more %s|wc -l', inputFileName);
[p,num_lines]=system(newcmd);
Thomas
Thomas 2012-4-11
can you give me a sample of your text file.?
douglas
douglas 2012-4-11
// Start Time: 0
// Sample rate: 10.0Hz
// Scenario: 1.8
// Firmware Version: 2.5.1
Year Month Day Second Temperature Acc_X Acc_Y Acc_Z Gyr_X Gyr_Y Gyr_Z Mag_X Mag_Y Mag_Z Roll Pitch Yaw AnalogIn_1 AnalogIn_2 Latitude Longitude Altitude Vel_X Vel_Y Vel_Z Status
0 0 0 0.0083 17.13 -3.602011 -0.023927 9.130322 0.002424 -0.003330 0.005214 0.551597 0.036565 -0.615183 -0.150150 21.529704 -6.936187 0 0 0.000000000 0.000000000 0.000000 0.000000 0.000000 0.000000 1
0 0 0 0.1083 17.13 -3.616401 -0.028699 9.101781 -0.013352 0.002609 -0.002676 0.546472 0.050605 -0.614217 -0.232993 21.544571 -6.953156 0 0 -0.000000001 0.000000000 -0.000094 -0.002426 -0.000193 -0.001876 1
0 0 0 0.2083 17.13 -3.626294 -0.006795 9.111114 0.005820 0.006014 0.006351 0.548270 0.048896 -0.615307 -0.185587 21.579128 -6.914592 0 0 -0.000000004 -0.000000001 -0.000314 -0.004752 0.003139 -0.002529 1
0 0 0 0.3083 17.13 -3.599662 -0.019086 9.139808 -0.003034 -0.001575 -0.005997 0.548736 0.048293 -0.615885 -0.216817 21.569953 -6.951937 0 0 -0.000000008 -0.000000004 -0.000515 -0.003222 0.004013 -0.001485 1
0 0 0 0.4083 17.13 -3.601782 -0.028687 9.101578 -0.001878 0.001172 -0.003753 0.542780 0.044977 -0.605897 -0.236359 21.576554 -6.975514 0 0 -0.000000011 -0.000000008 -0.000785 -0.003494 0.004624 -0.003916 1
0 0 0 0.5083 17.13 -3.592106 -0.028719 9.111055 -0.001411 0.002545 -0.002635 0.548381 0.045602 -0.610085 -0.250711 21.591040 -6.992247 0 0 -0.000000014 -0.000000013 -0.001272 -0.002378 0.005380 -0.005822 1
0 0 0 0.6083 17.13 -3.592194 -0.023880 9.120574 -0.012431 0.002142 -0.002905 0.545978 0.050608 -0.614250 -0.328819 21.603194 -7.010641 0 0 -0.000000015 -0.000000018 -0.001905 -0.000590 0.006776 -0.006842 1
0 0 0 0.7083 17.13 -3.631372 -0.019131 9.145054 -0.000406 0.001911 0.002302 0.547899 0.049894 -0.615344 -0.326204 21.614191 -6.996948 0 0 -0.000000016 -0.000000026 -0.002455 -0.001107 0.010194 -0.004149 1
0 0 0 0.8083 17.13 -3.601852 -0.028727 9.111190

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 采纳的回答

Thomas
Thomas 2012-4-11

1 个投票

You could try
for k = 58:212
inputFileName = sprintf('MT_%05i-000.txt',k);
outputFileName = sprintf('results%05i.tiff',k);
fid = fopen(inputFileName);
datacell=textscan(fid,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f');
if length(datacell)<=500 % this depends on the structure of datacell
actual_data=datacell(5:end) % removing only the 5 headerlines
fclose(fid);
else
actual_data=datacell(401:end) % removing 400 headerlines data > 500 rows
fclose(fid);
end
end
use only the actual_data for computation
EDIT: Try the following
for k = 58:212
inputFileName = sprintf('MT_%05i-000.txt',k);
outputFileName = sprintf('results%05i.tiff',k);
fid = fopen(inputFileName);
c=textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f','Headerlines',5,'delimiter',' ');
if length(c{1,1})<500 % this tell us there are less than 500 elements
datacell=textscan(fid,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f','Headerlines',5,'delimiter',' ');
fclose(fid);
else
datacell=textscan(fid,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f','Headerlines',400,'delimiter',' ');
fclose(fid);
end
end

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douglas
douglas 2012-4-11
it looks like the length(datacell) command spits out the number of columns, as I was getting it to equal 26
Thomas
Thomas 2012-4-11
try length(datacell{1,1})
douglas
douglas 2012-4-11
it seemed to work, but now its spitting out blanks plots and says
Warning: Plot empty.
> In legend at 294
In flighttestplot65 at 105
douglas
douglas 2012-4-11
since when length(c{1,1})<500
datacell = c,
I changed it to this,
inputFileName = sprintf('MT_%05i-000.txt',k);
outputFileName = sprintf('results%05i.tiff',k);
fid = fopen(inputFileName); %opens text file
c=textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f','Headerlines',5);
if length(c{1,1})<500 % this tell us there are less than 500 elements
datacell = c;
fclose(fid);
else
datacell = textscan(fid,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f','Headerlines',500);
fclose(fid);
end
and it now works for those files under 500, but it doesnt like defining the new datacell in the else statement for some reason
Thomas
Thomas 2012-4-11
It is because the new data cells are still blank when the header lines are around 400, try the opposite:
nputFileName = sprintf('MT_%05i-000.txt',k);
outputFileName = sprintf('results%05i.tiff',k);
fid = fopen(inputFileName); %opens text file
c=textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f','Headerlines',500);
if length(c{1,1})>1 % this tell us there are more than 500 elements
datacell = c;
fclose(fid);
else
datacell = textscan(fid,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f','Headerlines',5);
fclose(fid);
end
douglas
douglas 2012-4-11
it now has the opposite effect, where the sub 500 row sheets appear blank, and the larger ones look great. Which is good, since 95% of my text files are large.
Thomas
Thomas 2012-4-11
try this
else
fid = fopen(inputFileName); %opens text file add this line again
datacell = textscan(fid,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f','Headerlines',5);
fclose(fid);
douglas
douglas 2012-4-11
It seems to have fixed the problem!
Thank you so much for you help, you have been tremendous in assisting me!
Thomas
Thomas 2012-4-11
You are welcome.. Please accept the other answer as well since, it might help someone on a linux system..

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