Rename calc to math eval and allow it to optionally take an expression as an argument (#2195)

* Rename `calc` to `math eval` and allow it to optionally take the expression as an argument * Moved calc tests to math eval Also added 2 tests and changed 1 test * Move calc docs to math eval
2020-07-18 09:41:19 +05:30
parent 04e8aa31fe
commit ffe3e2c16b
11 changed files with 207 additions and 170 deletions
--- a/docs/commands/math-eval.md
+++ b/docs/commands/math-eval.md
@ -0,0 +1,158 @@
+# math eval
+
+math eval is a command that takes a math expression from the pipeline and evaluates that into a number. It also optionally takes the math expression as an argument.
+
+This command supports the following operations -
+
+operations:
+
+* binary operators: +, -, *, /, % (remainder), ^ (power)
+* unary operators: +, -, ! (factorial)
+
+functions:
+
+* sqrt, abs
+* exp, ln, log10
+* sin, cos, tan, asin, acos, atan, atan2
+* sinh, cosh, tanh, asinh, acosh, atanh
+* floor, ceil, round
+* signum
+* max(x, ...), min(x, ...): maximum and minimum of 1 or more numbers
+
+constants:
+
+* pi
+* e
+
+## Examples
+
+```shell
+> echo "1+2+3" | math eval
+6.0u
+```
+
+```shell
+> echo "1-2+3" | math eval
+2.0
+```
+
+```shell
+> echo "-(-23)" | math eval
+23.0
+```
+
+```shell
+> echo "5^2" | math eval
+25.0
+```
+
+```shell
+> echo "5^3" | math eval
+125.0
+```
+
+```shell
+> echo "min(5,4,3,2,1,0,-100,45)" | math eval
+-100.0
+```
+
+```shell
+> echo "max(5,4,3,2,1,0,-100,45)" | math eval
+45.0
+```
+
+```shell
+> echo sqrt(2) | math eval
+1.414213562373095
+```
+
+```shell
+> echo pi | math eval
+3.141592653589793
+```
+
+```shell
+> echo e | math eval
+2.718281828459045
+```
+
+```shell
+> echo "sin(pi / 2)" | math eval
+1.0
+```
+
+```shell
+> echo "floor(5999/1000)" | math eval
+5.0
+```
+
+```shell
+> open abc.json
+───┬──────
+ # │ size
+───┼──────
+ 0 │  816
+ 1 │ 1627
+ 2 │ 1436
+ 3 │ 1573
+ 4 │  935
+ 5 │   52
+ 6 │  999
+ 7 │ 1639
+───┴──────
+```
+
+```shell
+> open abc.json | format "({size} + 500) * 4"
+───┬──────────────────
+ # │
+───┼──────────────────
+ 0 │ (816 + 500) * 4
+ 1 │ (1627 + 500) * 4
+ 2 │ (1436 + 500) * 4
+ 3 │ (1573 + 500) * 4
+ 4 │ (935 + 500) * 4
+ 5 │ (52 + 500) * 4
+ 6 │ (999 + 500) * 4
+ 7 │ (1639 + 500) * 4
+───┴──────────────────
+```
+
+```shell
+> open abc.json | format "({size} + 500) * 4" | math eval
+───┬───────────
+ # │
+───┼───────────
+ 0 │ 5264.0000
+ 1 │ 8508.0000
+ 2 │ 7744.0000
+ 3 │ 8292.0000
+ 4 │ 5740.0000
+ 5 │ 2208.0000
+ 6 │ 5996.0000
+ 7 │ 8556.0000
+───┴───────────
+```
+
+```shell
+> open abc.json | format "({size} - 1000) * 4" | math eval
+───┬────────────
+ # │
+───┼────────────
+ 0 │  -736.0000
+ 1 │  2508.0000
+ 2 │  1744.0000
+ 3 │  2292.0000
+ 4 │  -260.0000
+ 5 │ -3792.0000
+ 6 │    -4.0000
+ 7 │  2556.0000
+───┴────────────
+```
+
+Note that since `math eval` uses floating-point numbers, the result may not always be precise.
+
+```shell
+> echo "floor(5999999999999999999/1000000000000000000)" | math eval
+6.0
+```