Reputation
Next tag badge:
133/100 score
17/20 answers
Badges
8 88 193
Newest
 functions
Impact
~430k people reached

May
16
comment Compute a hessian matrix on a image?
It looks like you might need ImageFilter, but there are also many built in filters that may do what you want.
May
15
reviewed Close Computing an integral numerically
May
15
reviewed Reviewed Computing an integral numerically
May
15
comment Computing an integral numerically
Please format your code and question to make it more readable. Help on editing can be found using the button on the top right of the edit box.
May
15
reviewed Close Can't seem to add another seed to rule 110
May
15
reviewed Close How do I get the adjacency Matrix from a random graph
May
15
comment How do I get the adjacency Matrix from a random graph
Use MatrixForm for displaying purposes only. Do not copy its result to use in any further calculation whatsoever.
May
15
reviewed Close The joint distribution of running maximum in two dimension
May
15
awarded  Nice Answer
May
15
revised What are the most common pitfalls awaiting new users?
Edit text about precedence.
May
15
comment Applying ReplaceAll to I (imaginary unit)
I agree the documentation could be clearer on that (it must be somewhere, but not on the ReplaceAll page). Luckily we have this covered in our popular Mathematica Pitfalls question.
May
14
awarded  Revival
May
14
answered Using Periodogram to investigate the seasonality of the data
May
14
comment Applying ReplaceAll to I (imaginary unit)
[...continued]. In your case (as stated in the comments) you want to replace -I, which is represented as Complex[0,-1] and I as Complex[0,1]. So -I/.I->-1 does nothing as it is equivalent to Complex[0,-1] /. Complex[0,1]->Complex[0,-1]. No match, so no replacement.
May
14
comment Applying ReplaceAll to I (imaginary unit)
The question you asked in the original post is not the question you actually have (as stated in your comments). Exp[I]/.I->-I works for me in 8, 9, and 10 (and for everybody else too). It seems your problem is actually` Exp[-I] /. I -> -I` which does not get you the result you expect. The point here is that ReplaceAll looks for structural matches in terms of the internal form of the expression. This internal form may differ from the way it is printed. 1-x for instance, is represented as Plus[1,Times[-1,x]]. You have to take this into account when replacing. [continues...]
May
14
reviewed Leave Closed Applying ReplaceAll to I (imaginary unit)
May
14
comment Applying ReplaceAll to I (imaginary unit)
Your addition is incorrect. I should not necessarily be entered as Complex[0,1]
May
14
reviewed Approve Why does Nintegrate keep unevaluated?
May
14
reviewed Close beginner's question: change a parameter while get variable answers
May
14
comment beginner's question: change a parameter while get variable answers
See also here.