Having two operating systems Windows 10 and Mageia 5 Linux helps sometimes... While Matlab R2015b in Windows 10 was just giving "unknown exception", Matlab R2015b in Mageia 5 was giving a clear reason "înv4fix is not a valid function name" ... Only then I saw that the first letter was not an i but î. Replacing it by a normal letter i solved this issue.
buildInstrumentedMex gives "Unknown exception"
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Bert RAM Aerts
on 21 Feb 2016
Edited: Bert RAM Aerts
on 23 Feb 2016
In the following code, the statement with buildInstrumentedMex gives the error "Unknown exception" while fiaccel is working fine. So the code generation must be OK. I do not have a license for code generation, but the examples from the Fixed Point Designer Getting Started Guide with buildInstrumentedMex are working fine. What am I missing?
T = mytypes('9Q23');
Hinp = cast(ones(2,2)+1j*ones(2,2),'like',T.x);
fiaccel inv4fix -args {Hinp,T} -o fiaccelinv4fix_mex
H1 = cast([ 0.1+1j*0.2 0.3+1j*0.4; 0.5+1j*0.6 0.7+1j*0.8 ],'like',T.x);
H1inv = fiaccelinv4fix_mex(H1,T);
buildInstrumentedMex înv4fix -args {Hinp,T} -histogram -o inv4fix_mex
where
% mytypes.m
function T = mytypes(dt)
switch dt
case '9Q23'
F = fimath('RoundingMethod', 'Nearest', ...
'OverflowAction', 'Saturate', ...
'ProductMode', 'SpecifyPrecision', ...
'ProductWordLength', 32, ...
'ProductFractionLength', 23, ...
'SumMode', 'SpecifyPrecision', ...
'SumWordLength', 32, ...
'SumFractionLength', 23, ...
'CastBeforeSum', true);
T.x = fi([],true,32,23,F);
end
end
% inv4fix.m
function Hinv = inv4fix(H,T) %#codegen
if size(H,1)==2;
% inverse of [a b; c d] is 1/(ad-bc) [d -b; -c a]
% fixed point types
Tdiv = numerictype('Signed',true,'WordLength',T.x.WordLength,'FractionLength',T.x.FractionLength);
% real algorithm
a = cast(H(1,1),'like',T.x);
b = cast(H(1,2),'like',T.x);
c = cast(H(2,1),'like',T.x);
d = cast(H(2,2),'like',T.x);
factor = cast((a*d - b*c),'like',T.x);
% 1/(a+1j*b) = (a-1j*b)/(a^2+b^2)
factor_r = cast(real(factor),'like',T.x);
factor_i = cast(imag(factor),'like',T.x);
denominator = cast(factor_r*factor_r + factor_i*factor_i,'like',T.x);
factor_r = divide(Tdiv,factor_r,denominator);
factor_i = divide(Tdiv,factor_i,denominator);
Hinv = [d -b; -c a];
Hinv = cast((factor_r-1j*factor_i) * Hinv,'like',T.x);
else
Hinv = H;
end
end
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