4.26.1 Top new questions this week

4.26.1.1 Replace elements that do not match a pattern

https://mathematica.stackexchange.com/questions/149736/replace-elements-that-do-not-match-a-pattern

 
I have the following matrix 
 
mat={{0,a,b},{c,0,d},{0,0,e}} 
 
 
I would like to replace the zero elements of it with 1 and the remaining with zero. The first step would be 
 
mat/.{0->1} 
 
 
However I  ...
 

- asked by Galuoises (12 votes), answered by eldo (7 votes)

4.26.1.2 Image segmentation by pixel value

https://mathematica.stackexchange.com/questions/149966/image-segmentation-by-pixel-value

 
I'm looking for a way to segment a grayscale image (or a 2D array) by its pixel values. We look at two neighboring pixels, if their values are close within a certain threshold, then we say they are  ...
 

- asked by xslittlegrass (11 votes), answered by nikie (11 votes)

4.26.1.3 Can trees be made into graphs?

https://mathematica.stackexchange.com/questions/151155/can-trees-be-made-into-graphs

 
When one has the output of a function like TreeForm, for instance: 
 
 
 
Can this be turned into a Graph object? I would like to be able to apply functions like VertexList, VertexDegree, AdjacencyList,  ...
 

- asked by M. Brandt (8 votes), answered by C. E. (5 votes)

4.26.1.4 Layout tips to keep UI responsive

https://mathematica.stackexchange.com/questions/149835/layout-tips-to-keep-ui-responsive

 
Bug introduced in V10.4 or earlier and persisting through V11.1.1 
 
 
CASE:3914402 
 
 
 
 
Here is an example of a problem I have. Gutted version of something much bigger: 
 
handler2 =  Framed[#,     ...
 

- asked by Kuba (8 votes), answered by Kuba (1 vote)

4.26.1.5 How to use $\LaTeX$ in Mathematica text

https://mathematica.stackexchange.com/questions/151102/how-to-use-latex-in-mathematica-text

 
I would like to formulate a question in a notebook for my students using $\LaTeX$ (or $MathML$) to typeset functions and matrices. I specifically want a language other than Mathematica as students  ...
 

- asked by user49947 (7 votes), answered by Nasser (6 votes)

4.26.1.6 getting zero for special positions in a matrix

https://mathematica.stackexchange.com/questions/149767/getting-zero-for-special-positions-in-a-matrix

 
There are a list 
 
list={{1, 2, 3, 2, 3}, {3, 1, 1, 2, 3}, {3, 2, 1, 3, 2}, {1, 2, 1, 1, 1}}; 
 
 
I wish to have all elements be zero except the first and the fourth in each row: desired: 
 
list={{1, 0,  ...
 

- asked by Irreversible (7 votes), answered by tomd (7 votes)

4.26.1.7 To Work with Barchart or DiscretePlot?

https://mathematica.stackexchange.com/questions/149960/to-work-with-barchart-or-discreteplot

 
I would like to create a graph similar to this below using some slightly dotted bar style like the one shown in the figure ... 
 
 
 
And I'm trying to open a space between bars 6 and 8, but I'm failing. 
 
...
 

- asked by LCarvalho (7 votes), answered by kglr (6 votes)