Octave has limited support for nested functions. That is
function y = foo (x)
- y = bar(x)
+ y = bar (x)
function y = bar (x)
y = ...;
end
@@ -88,7 +88,7 @@
is equivalent to
function y = foo (x)
- y = bar(x)
+ y = bar (x)
end
function y = bar (x)
y = ...;
@@ -253,7 +253,7 @@
behaviour, you can enable it since Octave 3.4.0 with the following
command:
- do_braindead_shortcircuit_evaluation(1)
+ do_braindead_shortcircuit_evaluation (1)
Note that the difference with Matlab is also significant when
either argument is a function with side effects or if the first argument
@@ -278,7 +278,7 @@
logically true).
Finally, note the inconsistence of thinking of the condition of an if
-statement as being equivalent to all(X(:)) when X is a
+statement as being equivalent to all (X(:)) when X is a
matrix. This is true for all cases EXCEPT empty matrices:
if ([0, 1]) == if (all ([0, 1])) ==> i.e., condition is false.
@@ -315,7 +315,7 @@
is equivalent to
function x = mldivide (A, b)
- [Q, R, E] = qr(A);
+ [Q, R, E] = qr (A);
x = [A \ b, E(:, 1:m) * (R(:, 1:m) \ (Q' * b))]
end
@@ -326,26 +326,26 @@
A numerical question arises: how big can the null space component
become, relative to the minimum-norm solution? Can it be nicely bounded,
or can it be arbitrarily big? Consider this example:
-
+OctaveFAQ.texi
m = 10;
n = 10000;
- A = ones(m, n) + 1e-6 * randn(m,n);
- b = ones(m, 1) + 1e-6 * randn(m,1);
- norm(A \ b)
+ A = ones (m, n) + 1e-6 * randn (m,n);
+ b = ones (m, 1) + 1e-6 * randn (m,1);
+ norm (A \ b)
while Octave's minimum-norm values are around 3e-2, Matlab's
results are 50-times larger. For another issue, try this code:
m = 5;
n = 100;
- j = floor(m * rand(1, n)) + 1;
- b = ones(m, 1);
- A = zeros(m, n);
- A(sub2ind(size(A),j,1:n)) = 1;
+ j = floor (m * rand (1, n)) + 1;
+ b = ones (m, 1);
+ A = zeros (m, n);
+ A(sub2ind (size (A),j,1:n)) = 1;
x = A \ b;
- [dummy,p] = sort(rand(1,n));
- y = A(:,p)\b;
- norm(x(p)-y)
+ [dummy,p] = sort (rand (1,n));
+ y = A(:,p) \ b;
+ norm (x(p)-y)
It shows that unlike in Octave, mldivide in Matlab is not invariant
with respect to column permutations. If there are multiple columns of
@@ -424,10 +424,10 @@
second case the variable "a" is reset correctly. Therefore Matlab
gives no safe way of temporarily changing global variables.
-
sin(x)(1:10); for example is perfectly valid
in Octave but not Matlab. To do the same in Matlab you must do
-y = sin(x); y = y([1:10]);
+y = sin (x); y = y([1:10]);
Indexing other things than variables is possible, as in:
octave:1> [3 1 4 1 5 9](3)
ans = 4
- octave:2> cos([0 pi pi/4 7])(3)
+ octave:2> cos ([0 pi pi/4 7])(3)
ans = 0.70711