For questions on interpreting existing error messages that you have encountered, as well as writing and managing messages, assertions and checks for your own functions.

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21
votes
4answers
3k views

Importing a large Excel file

I'm trying to import a simple Excel file containing 94,000 rows and 52 columns of various types, mostly Reals. It's a 38-MB file. I get this super helpful error ...
6
votes
1answer
419 views

What does MaxStepFraction do?

I find that with NDSolve[...] while solving a partial differential equation, changing the MaxStepFraction from ...
2
votes
2answers
1k views

NMinimize with defined function call getting error NMinimize::nnum

I want to call the NMinimize function for my own defined calculations but I got an error. Below is a simple example. ...
28
votes
4answers
2k views

Why does MatrixForm affect calculations?

This is a really newbie question, but it has me confused. Why does this code work without // MatrixForm and doesn't work with ...
4
votes
2answers
242 views

Indeterminate expression. Where?

Consider the following: ...
2
votes
1answer
1k views

Mathematica Can't Evaluate This?

I am trying to find the inverse function of $\frac{\ln{x}}{x^2}$ in Mathematica. I am using the Solve[] function to find the inverse (yes, I know about ...
41
votes
2answers
1k views

Mathematica Debuggability

One of the things that I really dislike about Mathematica is its lack of debuggability compared to many other programming languages. Some of the problems arises from the functional nature of ...
2
votes
1answer
816 views

A combination of Set::setraw and Set::shape errors

Please consider the following toy code: ...
8
votes
2answers
804 views

Table function with Part[] call misbehaving, but only after initial startup of Mathematica

I am getting errors like: Part::partd: Part specification standardBasis[[1]] is longer than depth of object. with the following Manipulate expression: ...
11
votes
3answers
4k views

General::ivar is not a valid variable when plotting - what actually causes this and how to avoid it?

I was just evaluating a couple of expressions and started to get errors like this: ...
28
votes
1answer
476 views

which is better, using Assert[] or manual checks on arguments and other computations?

I never used Asserts in Mathematica, but trying to see what advantage they have over just argument check and additional definitions of the function to capture unwanted input. For example, which one ...
47
votes
2answers
1k views

What are the best practices / most common / idiomatic ways to report errors in Mathematica?

In particular, what are the best ways to report errors about incorrect arguments to a function? Checking for the correct arguments is relatively easy using patterns, but how to report an informative ...