MrMarc

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12 years, 312 days

MaplePrimes Activity


These are questions asked by MrMarc

I have this data I want to import in to Maple.




In Maple I type:

ImportMatrix("C:\\Users\\marc\\Desktop\\data1.csv", delimiter = ",");

then I get the following:




My question now becomes how can I import the data with the correct dates and not just -Aug, 1-Aug etc ?
The method should also work when I have many more columns of dates.

Ps I cant upload the data on MaplePrimes since it is a csv file.

Ok so I managed to get my data into a google spreadsheet by using a google app script (JavaScript in the cloud).
The data is updated daily. I now want to access it from Maple. Axel has helped me write the following
procedure to do just that for (https websites and not just http):

X := proc (Url) local theDLL, URLDownloadToFile, myDirectory, myFile, Destination, DL;

theDLL := "C:\\WINDOWS\\SYSTEM32\\urlmon.dll";

URLDownloadToFile := define_external('URLDownloadToFileA', pCaller::(integer[4]), szURL::string, szFileName::string, dwReserved::(integer[4]), lpfnCB::(integer[4]), 'RETURN'::(integer[4]), LIB = theDLL);

FileTools:-MakeDirectory("C:\\mydir");
myDirectory := "C:\\mydir";
myFile := "data1.csv";
Destination := cat(myDirectory, "\\", myFile);

DL := proc () URLDownloadToFile(0, Url, Destination, 0, 0);
ImportMatrix("C:\\mydir\\data1.csv", source = csv)
end proc;

return DL(), FileTools:-RemoveDirectory("C:\\mydir", recurse = true, forceremove = true)

end proc:


X("https://docs.google.com/spreadsheets/d/1L5-yUB0EWeBdJNMdELKBRmBQ1JJ0QymrtDLkVhHCVn8/edit?usp=sharing");

 

However now I get an error message saying:

Error, (in ImportMatrix) no delimiter found after line 768, column 2


Any ideas how to solve this?

I want to extract all the symbols and last trade from 

http://finance.yahoo.com/q/cp?s=%5EIXIC

I have tried:

status, data, headers := HTTP:-Get("http://finance.yahoo.com/q/cp?s=%5EIXIC");
data;

but it just gives me a bunch of jiberish! Any ideas?

When you use the slider without Do(%MathContainer1 = StandardError(Variance, R)):
everything works ok but when you add Do(%MathContainer1 = StandardError(Variance, R)):
Maple Crashes.....

Strange...

LL_102)_Covariance_M.mw

How can I get the Standard Errors of the covariance matrix in Maple?
I can simulate a covariance matrix in Maple as follows:

restart:
with(Statistics):
with(LinearAlgebra):

R := RandomMatrix(4, 4, generator = -15 .. 15, outputoptions = [datatype = float[8]]);
CovarianceMatrix(R);

but how do I find the standard errors?

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