# Linked Questions

26 questions linked to/from Does Mathematica have advanced indexing?
2answers
179 views

### Achieve performance that is competitive with numpy [duplicate]

What are the best practices to ameliorate time performance of Mathematica? As a practical example how we can decrease timing below? ...
2answers
806 views

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2answers
111 views

### Threshold elements in a table [duplicate]

I'm new to Mathematica. I hope this is not a too stupid question, but I couldn't find a solution in the Mathematica documentation. My question is about creating a function to iterate over the ...
1answer
140 views

### Is there a cleaner/shorter way to select-replace in matrices? [duplicate]

I love Mathematica, but I find it oddly lacking when it comes to how matrices are handled. Here is an example of code that works but seems like it should be a lot shorter (and minus the loop). I'm ...
1answer
111 views

### An equivalent in Mathematica [duplicate]

Let's say I have a $n$x$m$ matrix $M$ in Matlab and I want to substitute the elements of $M$ that exceed $15$ for $-1$. In Matlab I just write M(M>15)=-1 and ...
1answer
58 views

### Choosing data from list and plot [duplicate]

I have a data set like below: Angle={5.48575, -0.669213, 45.9832, 8.63878, -16.8777, 50.022, -41.8882, -45.956, 28.3005, 35.8234} Now want to select the ...
8answers
8k views

### Can one identify the design patterns of Mathematica?

... or are they unnecessary in such a high-level language? I've been thinking about programming style, coding standards and the like quite a bit lately, the result of my current work on a mixed .Net/...
6answers
2k views

### Element-wise test on List elements

This question could sound pretty silly but I can't find a way to apply element -wise tests to a list. For example if I digit ...
6answers
831 views

### Sierpinski carpet with GraphData

Is this graph in the list among the so-called "standard" structures used in GraphData? However, I have not found yet anything like "Carpet" or "Sponge" in the list ...
1answer
2k views

### Why are numeric division and subtraction not handled better in Mathematica?

There is something that has been troubling me for a while. At least through version 10.0 the performance of a / b and a - b is ...
4answers
3k views

### Why is ParallelTable slower than Table?

Update Following a comment of Szabolcs have changed Timing to AbsoluteTiming. The results are virtually the same. Original post I have accidentally observed the following surprising result. So, why ...
3answers
1k views

### Emulating R data frame getters with UpValues

What's the best way to emulate R's data frames functionality? This includes the ability to select rows and columns in a 2-dimensional table by the string identifiers positioned typically in the first ...
3answers
759 views

### Select seems unusually slow

I haven't been doing nearly as much Mathematica as I really should for the past few months, and in order to get my head back in the game I've been using it to run roughshod over easy Project Euler ...
4answers
512 views

### Speed of a simple operation over a long list

What is the fastest procedure for counting elements smaller than 0.5 in a large list? For example let list=RandomReal[1, 10000000]; For a number of elements ...
4answers
252 views

### Concise alternative to First@First@Position[…, 1,Heads->False]

Is there a more compact way to accomplish this: lst = {0,0,7}; idx = Position[lst, Except, 1, Heads -> False] // First // First (* => 3 *) For ...

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