All Questions

Tagged with
Filter by
Sorted by
Tagged with
9
votes
1answer
277 views

Why ArcTan[1, 0. I ] yields -1.5708+0. I?

Bug introduced in 5.2 or earlier and persisting through 12.0.0 Why ArcTan[1, 0. I ] yields -1.5708+0. I ? The result should ...
6
votes
0answers
63 views

Where is the mistake in computing the particular eigenvector of the following DFT Matrix?

I have the following matrix (the DFT Matrix for N = 3) $$W = \frac{1}{\sqrt{3}}\begin{pmatrix} 1 & 1 & 1 \\ 1 & e^{-\frac{i 2 \pi}{3} } & e^{\frac{i 2 \pi}{3} } \\ 1 & e^{\frac{...
2
votes
2answers
87 views

Incorrect result for the region of convergence of a simple integral

Bug persisting at least through version 11.3.0 The standard Gaussian integral Integrate[Exp[-a x^2], {x,-Infinity,Infinity}] returns ...
6
votes
2answers
200 views

Series expansion gives incorrect result

Bug introduced after 10.4 and persisting through 11.3.0 Mathematica 11.1.1.0 tells me that ...
1
vote
2answers
142 views

Improper ParametricPlot3D result when using certain complex numbers

Bug introduced in 8 or earlier and persisting in 11.1 This is more out of curiosity than for any project that I'm working on. I was experimenting with the ParametricPlot3D and put in the following ...
8
votes
1answer
267 views

Symbolic and numeric limit disagreeing on branch cut of ArcTan

Bug introduced after 8.0.4 and before 9.0.1 and fixed in 11.1.0. Investigating comments to my previous question lead me to the following problem: ...
9
votes
2answers
327 views

Integrate and NIntegrate disagreeing over branch cut of Sqrt?

Bug introduced after 8.0.4 and before 9.0.1, and fixed in 11.1.0. In Mathematica 10.2 I'm trying to integrate this piecewise continuous function, but Integrate and ...
9
votes
2answers
335 views

Strange behavior of Limit in Mathematica 9 and 10 (bug?)

fixed in 10.1 Consider a complex logarithm where the branch cut is defined along the negative axis. Then for $r$ and $\eta$ real and positive we can write $ \lim_{\eta \to 0} \log(-r+ i \eta) = log (...
9
votes
3answers
157 views

Pattern matching with Complex. Feature or a bug?

fixed in 10.1 (windows) I have run into some strange behavior while doing some pattern matching. First, this works as expected: ...
2
votes
0answers
421 views

Simple contour integral with a parameter gone wrong

Bug introduced in 7.0 and fixed in 7.0.1 I run into the following problem, I tried to evaluate a very simple integral: ...