Quickly Evaluate Infix Math Expression?

Question

Is there a way to highlight and quickly evaluate a simple math expression without using elisp notation? For example, we can already evaluate the elisp expression (+ 1 1) in the following text snippet by putting point behind it and pressing C-x C-e.

Here is a math equation: (+ 1 1)

But can we also do

Here is a math equation: 1 + 1

And get its result?

score 8 · Answer 1 · answered Jan 29 '18 at 02:11

8

You can use the built-in calc package to do so.

Mark your expression, e.g. 3 * (1 + 1)
Call calc-grab-region
- Call calc-dispatch (default C-x *), then hit g

answered Jan 29 '18 at 02:11

Tianxiang Xiong

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1

You can also use `C-u C-x * e` while the expression is marked, and the marked expression will be replaced by the result. Afterwards, use `C-x * x` to exit calc. – Dodgie Jan 30 '18 at 22:44
I just tried this, and did not need to perform the second step `calc-dispatch g`. – user1404316 Feb 09 '18 at 15:21
I meant `calc-dispatch`, then `g` performs `calc-grab-region`. – Tianxiang Xiong Feb 09 '18 at 18:14

Dieter.Wilhelm · Answer 2 · 2018-02-01T15:12:33.807

3

You might also use calc's embedded mode if you intent to replace an expression with its result in the current buffer. C-u C-x * e when your formula / expression is on it's own on a separate line.

Otherwise mark it and type C-0 C-x * e

(Update: thanks to Dodgie, forgot to mention that) When you are finished with your mathematical manipulations type C-x * e again to end embedded calc mode.

edited Feb 01 '18 at 15:12

answered Jan 30 '18 at 22:09

Dieter.Wilhelm

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Quickly Evaluate Infix Math Expression?

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