ORDEIG fails
Hi Pavel,
I hope you are doing fine?! I'm running Advanpix Version 3.9.4 Build 10481 on Windows and ORDEIG crashes MATLAB 2015B with a "FatalException" on the following problem:
KK = [ mp('1.2856486930664507983834710103110410e+00'), mp('0.0000000000000000000000000000000000e+00') ;
ee = ordeig(HH,KK);
When calling ordeig(double(HH),double(KK)), everything works fine. Please see below for my mp.Info output and the crash report.
Cheers, Stefan
>> mp.Info
This error was detected while a MEX-file was running. If the MEX-file
(I CAN SEND YOU THE CRASH DUMP IF NECESSARY.)
Missing accumarray()
Hello,
I need to implement MATLAB built-in function accumarray(), which is not supported by the Advanpix toolbox (yet?). In order to use the same code for single/double/mp precision, I tried to overload accumarray by creating a new function in the mp class. Whenever I want to pass a vector of mp values to that function, it gets "messed up".
I have put this piece of code into the methods section of mp class:
function result = accumarray(subs, val, sz)
size(val)
val(1)
val(2)
keyboard
...
end
The code...
>> accumarray([1; 2; 2; 1; 1], mp([1;2;3;4;5]))
...returns...
ans =
5 1
ans =
1
2
3
4
5
Index exceeds matrix dimensions.
Error in mp/accumarray (line 5038)
val(2)
As you can see, the second argument has still its size (and numel) but all the content was somehow shrinked into the first element. Could you, please, help me with implementing of my own methods into the toolbox?
Best regards,
Vladimir
Bsxfun with empty input
Hello,
I think I have found bug/different behavior in bsxfun():
a = pi;
a(1) = [];
bsxfun(@plus, a, ones(4,1))
...returns...
ans =
Empty matrix: 4-by-0
but
a = mp('pi');
a(1) = [];
bsxfun(@plus, a, ones(4,1))
...returns...
Error using mp/subsref (line 990)
Index exceeds matrix dimensions.
Error in mpbsxfun (line 71)
Error in mp/bsxfun (line 1132)
[varargout{1:nargout}] = mpbsxfun(varargin{:});
I am running:
MATLAB Version: 8.5.0.197613 (R2015a)
Multiprecision Computing Toolbox, (c) 2008-2017 Advanpix LLC.
Version : 4.3.2 Build 12170
Platform: Win64
Release : 2017-01-16
Trial version. Valid until 2017-01-30
Best regards,
Vladimir
Error for boolean operation at certain precision
Hello Pavel.
I got the following problem:
mp.Digits(349);
array=mp('2')*mp('10')^mp('-4'):mp('2')*mp('10')^mp('-4'):mp('1');
array(1,100)==mp('0.02')
ans =
logical
1
mp.Digits(350);
array=mp('2')*mp('10')^mp('-4'):mp('2')*mp('10')^mp('-4'):mp('1');
array(1,100)==mp('0.02')
ans =
logical
0
mp.Digits(351);
array=mp('2')*mp('10')^mp('-4'):mp('2')*mp('10')^mp('-4'):mp('1');
array(1,100)==mp('0.02')
ans =
logical
1
This apperas quite randomly, deppending on the used precision. You can try for example mp.Digits(352) to mp.Digits(355).
Thank you for your help.
SVD behavior in mp different from Matlab when applied to negative scalar
I have the following question:
In one of my examples I need to compute the Singular Value Decomposition (SVD) of a negative scalar, specifically -0.7276.
In double precision, Matlab returns:
>> [U S V]=svd(-0.7276)
In MP, I obtain:
s=mp('-0,7276');
>> [U,S,V]=svd(s)
The definition of SVD states that the matrix S should have nonnegative diagonal entries. In the above example, the first two elements seem to be multiplied by -1 compared to Matlab output. While the product doesn't change, the unexpected negative sign of the singular value causes problems in subsequent code.
Is this a bug or is there an option to make it return the same output as Matlab's svd?
The 4.2.3.11967 release of the toolbox was used.
Thank you,
Denis
Dear Denis,
Thank you very much for the report!
Indeed, this is bug and it has been fixed in latest build.
Please download updated version: http://goo.gl/pMXV3
Thank you,
Pavel.
How can I run FresnelS and FresnelC functions?
When I add the multiprecision computing toolbox and type FresnelS(1) in matlab command, I get the following error message.
Cannot find an exact (case-sensitive) match for 'FresnelS'
The closest match is: fresnels in C:\Program
Files\MATLAB\R2016a\toolbox\symbolic\symbolic\@double\fresnels.m
Also, when I type fresnels(mp(1)), I get
Undefined function 'fresnels' for input arguments of type 'mp'.
How can I solve this problem?
Nonequidistant FFT
Dear Pavel,
It would be great to support the non-equidistant Fast Fourier Transform.
https://www-user.tu-chemnitz.de/~potts/nfft/
Regards,
Didier
Integer matrix
I have matrices they are made of integers. Do I need to define mp even for integers? For example:
N=100;
A=(zeros(N+1,N+1));
for l=1:N;
for k=mod(l-1,2):3:l;
A(k+1,l+1)=3*l;
end
end
and
p=0:1:N;
kron(p',p);
and
I=ones(N+1,1);
II=(-1).^(0:N);
G=kron(I,II);
Integer is normally considered as infinite precision. I use these matrices in further calculation with non-integer matrices, therefore, results. But using mp.Digits(100) for example costs me a lot in here for no gain actually.
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