Fast calculation of short cumulative product vector
Nobody has followed Knut's suggestion: y(n) = y(n-1)*y(1) It is in fact a special case of Horner's Method for evaluating a...

11 years ago | 0

alternative to log?
No matter what transformation you use, the result, prod(pi, i=1:n) --> 0, so eventually you will get underflow in fixed precisio...

11 years ago | 0

Loop unrolling question
Most of those manuals or books are out of date, or are unaware of the JIT compiler, or do not understand what the JIT compiler d...

11 years ago | 0

Loop unrolling question
David, What you call _loop unrolling_ is not. Here is a rolled-up loop: for i = 1:n a(i) = b(i)*c(i) end ...

11 years ago | 0

Why does 1 - 2/3 - 1/3 not equal zero?
Ned, Let me add to the confusion by asking 1. Why does |en1 = (1 - 2/3) - 1/3 = 5.5511e-017 = 2^(-54) = eps/2^2|? 2. Why does...

11 years ago | 1

Question

What does RANDPERM miss?
Abstractly, a random permutation generator (RPG) is a function that maps a random bit-string of length |b| into a permutation of...

11 years ago | 4 answers | 1

### 4

How to average only positive values in an array?
At the risk of offending the "vectorizers", the function below is 2 to 3 times faster than Jan's answer: function MeanP...

11 years ago | 0

MATLAB's accuracy of digits number
Here is a quotation from Prof Nick Trefethen FRS, Oxford: 11. _No physical constants are known to more than around eleven digit...

11 years ago | 0

An answer should _illuminate_ not _dazzle_.

11 years ago | 2

random elements from specific rows in matrix
function rrelems = RandRowElems(A) % USE: m = 10; n = 10^6; % A = ceil(100*rand(m,n)); % tic;relems =...

11 years ago | 0

Question

What is the "best" way to Generate a Bernoulli Process?
A *Bernoulli Process* is a sequence of iid (independent, identically-distributed) random variables |x1,x2,...,xi,...|, where t...

11 years ago | 3 answers | 1

### 3

In certain cases the profiler is worse than useless -- it is misleading. As you will have noticed, the profiler adds a lot of ov...

11 years ago | 0

Does MATLAB have a Birthday Problem?
Reply from Derek O'Connor: I must apologize for the omission of the RNG used. It was in my original draft but somehow got left ...

11 years ago | 1

| accepted

Question

Does MATLAB have a Birthday Problem?
The Birthday Paradox or problem asks for the probability that in a room of n people, 2 or more have the same birthday (not date)...

11 years ago | 5 answers | 3