Matlab takes in wrong data in command window
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[fname, pname] = uigetfile('*.csv'); %ask for file
filename= fullfile(pname, fname); %file as string
assert(exist(filename, 'file')==2,'%s does not exist.', filename); %check if file exist
data = csvread(filename, 1) % reads data from file skipping headers
***************************Excel Data***************
(just need to shift values to according heading, they are in order)(there are like 55,000 rows but these are the first couple)
Latitude Longitude Elevation (metres) Distance (KMs) Gradient
30.6183 -96.33631 103.7 0 0
30.61832 -96.33629 103.6 0.003 0
30.61845 -96.3361 102.8 0.026 0
30.61845 -96.33608 102.7 0.028 0
**************************Data from Matlab************************
0.0363 -0.1203 0.1592 2.7105 0
0.0363 -0.1203 0.1595 2.7105 0
0.0363 -0.1203 0.1595 2.7106 0
0.0363 -0.1203 0.1578 2.7106 -0.0010
0.0363 -0.1203 0.1571 2.7107 -0.0020
5 个评论
dpb
2017-6-12
As I commented in the duplicate of this question already, need to see the actual file--attaching a short section of it would be ideal.
I've never had Matlab not correctly read a variable if it were properly formatted and the correct format string, etc., used to read it so there's something going on in the file we're not seeing.
Or, as mentioned there as well, perhaps you're not opening the file you think you are???
hi hey
2017-6-12
hi hey
2017-6-12
Image Analyst
2017-6-12
编辑：Image Analyst
2017-6-12
He meant to attach your CSV file, NOT a screenshot. Please attach a CSV file that demonstrates the problem so we can replicate it.
What's showing in the Excel screenshot is not the kind of CSV file that MATLAB likes. It should be just numbers, not numbers and text with some rows of numbers having different numbers of columns than other rows.
hi hey
2017-6-12
采纳的回答
Image Analyst
2017-6-13
1 个投票
The data from MATLAB is the same, it's just that when you echo it to the command window, the data is multiplied by 1e-3. If you use fprintf() instead of just letting it automatically echo to the screen, you'll see they are the same (I tried it).
11 个评论
dpb
2017-6-13
Actually you're right IA--I thought I'd checked and there wasn't the right value...wonder what triggers the difference in the command window display between reading with csvread and textread? I've not noticed that behavior previously...altho it surely is as been shown this thread repeatable...
Image Analyst
2017-6-13
I don't know. Sometimes it just automatically decides to convert numbers spewed out to the command window to exponential notation. Perhaps you can avoid it by issuing the command
format long g
dpb
2017-6-13
If I get a chance't I'll look a little--wonder if there's a possibility of a floating-pt rounding difference between two competing i/o routines that triggers just enough of a numerical difference to trigger the display logic...peculiar.
I'll just delete my above response--it tends to obfuscate the real issue.
Well, that isn't it (and I thought would be really bizarre if so)--
>> d=textread('route.csv','','headerlines',1,'delimiter',',');
>> dcsv=csvread('route.csv',1);
>> all(d(:)==dcsv(:))
ans =
1
>>
But switching back and forth which function is called triggers the change in command window presentation repeatably...
csvread calls dlmread which is just a wrapper for textscan while textread is implemented in its own venerable mex-file so I thought perhaps that might have a rounding one-bit fp difference or the like that was just enough.
hi hey
2017-6-13
Image Analyst
2017-6-13
It's not incorrect. It's just scrolling the part that says x1e-3 past the top of the command window when you echo it there. So it's only the display that looks different. Just try it, the numbers in your calculations will be correct.
hi hey
2017-6-13
Walter Roberson
2017-6-13
That "first row from matlab" is not the first row: the rest of the data has scrolled off the top of the screen.
dpb
2017-6-13
>> csvread('routeshort.csv',1)
ans =
1.0e+03 *
0.0306 -0.0963 0.1037 0 0
0.0306 -0.0963 0.1036 0.0000 0
0.0306 -0.0963 0.1028 0.0000 0
0.0306 -0.0963 0.1027 0.0000 0
0.0306 -0.0963 0.1024 0.0000 0
0.0306 -0.0963 0.1018 0.0000 0
0.0306 -0.0963 0.1017 0.0000 -0.0040
0.0306 -0.0963 0.1017 0.0001 -0.0040
0.0306 -0.0963 0.1016 0.0001 -0.0040
...
>> d=textread('route.csv','','headerlines',1,'delimiter',',');
>> d(1:5,:)
ans =
30.6183 -96.3363 103.7000 0 0
30.6183 -96.3363 103.6000 0.0030 0
30.6184 -96.3361 102.8000 0.0260 0
30.6184 -96.3361 102.7000 0.0280 0
30.6184 -96.3361 102.4000 0.0310 0
>>
I'd revert to the previous comment re: csvread and needing to also see precisely what you've done in code in command line...I've got to think you're just not actually comparing the same files, though, somehow, but it's not easy when don't have access to the workstation to be able to see just what, specifically, might be the issue.
Image Analyst
2017-6-13
You can see in dpb's post that both csvread() and textread() have the same numbers, they're just formatted differently in the display. csvread has the 1.0e+03 in there whereas text read doesn't. But internally, in your code, using the arrays from either function will give you the same result. If you echo to the command line, the 1.0e+03 just scrolled off the top of the command window, like Walter and I said, but it's still the same numbers. So I'd use csvread() (if you have a recent version where you can tell it to skip a header line) since textread() is deprecated.
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