Effacer les filtres
Effacer les filtres

Check range for power function

6 vues (au cours des 30 derniers jours)
Life is Wonderful
Life is Wonderful le 14 Sep 2021
I am looking for a unit test vectors which checks the range of input values for power function so that I can implement equivalent of C type in fix point
A = fi([1:2^5/32:2^5],0,32); % A > 0, so it starting with lowest positive fraction value
B = fi([-2:1e-2:2],1,32);
% C = power(A,B) % seeking help here for C type power implementation but
% gettting error
% % Error using fixed.internal.power.validateK (line 13)
% % Exponent input to 'power' must be a real scalar and the value must be a non-negative integer.
% %
% % Error in fixed.internal.power.powImpl>validateInputs (line 39)
% % fixed.internal.power.validateK(k);
% %
% % Error in fixed.internal.power.powImpl (line 9)
% % validateInputs(a, k);
% %
% % Error in .^ (line 32)
% % y = fixed.internal.power.powImpl(a, k);
figure(100);
A = [1:32];
B = [-2:2];
hold on; grid on;
plot(power(A(1),B(1:end)),'r-.');
plot(power(A(2),B(1:end)),'g-.');
plot(power(A(3),B(1:end)),'b-.');
plot(power(A(4),B(1:end)),'m-.');
%.
%.
%.
%.
plot(power(A(32),B(1:end)),'k-.','linewidth', 2.0);

Réponses (1)

Walter Roberson
Walter Roberson le 14 Sep 2021
When you use fi, the power must be a positive integer scalar.
Also, log(A) does not appear to be supported so you cannot use the usual exp(log(A) .* B)
You will need to implement your own fractional power, perhaps using a CORDIC method.
  3 commentaires
Life is Wonderful
Life is Wonderful le 14 Sep 2021
Modifié(e) : Life is Wonderful le 14 Sep 2021
y = cordiccexp(log(1) .* -2);
y
y = 1.0000 - 0.0000i
y = power(2,cordiccexp(log(2) .* -2))
y = 0.8820 - 0.7153i
z = power(2 ,-2)
z = 0.2500
y = nthroot(1,-2);power(2,y) % IS THIS YOUR INTERPRETATION OWN FRACTIONAL POWER
ans = 2
Life is Wonderful
Life is Wonderful le 16 Sep 2021
I could see following case for computing the power with base and exponent condition
A is integer and B is exponent
if A < 0 && B < 0
C = power(A,B);
elseif A > 0 && B < 0
C = power(A,B);
elseif A == 0 && B < 0
C = power(A,B);
elseif A > 0 && B == 0
C = power(A,B);
elseif A > 0 && B > 0
C = power(A,B);
end

Connectez-vous pour commenter.

Catégories

En savoir plus sur MATLAB dans Help Center et File Exchange

Tags

Produits


Version

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by