zcalc

zhengxyz123's calculator. A simple scientific calculator in 1,000 lines!

Usage

Type

python3 zcalc.py

in command line to enter interactive mode.

Or type

echo "1+2+3+4+5" | python3 zcalc.py

to calculate the expression immediately.

Settings

You can use the following command to change calculator setttings:

set <a_setting_name>=<an_integer_value>

Available settings are:

Name	Description	Default Value	Notes
precision	Precision in display	15
base	Numeric base in display (just for integers)	10	(1)
enable_num2str	Whether or not to enable num2str	1	(2)

Notes:

1. Available options are 2, 8, 10 and 16.
2. Pass 0 to disable it. Learn more about num2str.

There are some undocumented settings, you can find them inside the source code. Changing the values of these settings is not recommended.

To get the current value of a setting, enter:

get <a_setting_name>

Readline Completer

If you can't remember the names of the settings described in the table above, as well as the names of all keywords and functions described below, zcalc provides the ability to use the tab key to complete the syntax.

This feature is not available on platforms that do not have the readline module installed.

Calculating

zcalc only supports two types of numbers: int and float. Binary, octal and hexadecimal integers are also supported.

zcalc uses the same operator as Python, except:

In zcalc	In Python
!	~
&&	&
||	|

zcalc provides a lot of functions, they are:

• Number-theoretic and representation functions: abs(x), ceil(x), comb(n, k), factorial(n), floor(x) and perm(n, k=None)
• Power and logarithmic functions: cbrt(x)(Python 3.11 and above), exp(x), expm1(x), lg(x), ln(x), log(x, base=e) and sqrt(x)
• Trigonometric functions: acos(x), asin(x), atan(x), atan(y, x), cos(x), sin(x) and tan(x)
• Angular conversion functions: degrees(x) and radians(x)
• Hyperbolic functions: acosh(x), asinh(x), atanh(x), cosh(x), sinh(x) and tanh(x)
• Special functions: erf(x), erfc(x), gamma(x) and lgamma(x)

zcalc also defines 3 constants that cannot be reassigned: e, pi and tau.

The ans variable stores the result of the last calculation.

zcalc uses a five-point template to compute numerical differentiation. If you want to calculate $\frac{\mathrm{d}}{\mathrm{d}x}\sin x|_{x=\pi}$, type:

diff sin(x)|x=pi

zcalc uses Adaptive Simpson′s Rule to compute numerical differentiation, if you want to calculte $\int_1^2e^x\mathrm{d}x$, enter:

int e**x|x=1~2

zcalc uses Newton's method to solve equations. If you want to solve $\sin x=\frac{1}{2}$, type:

solve sin(x)-1/2|x=1

If you want to calculate $\sum_{n=1}^{100}2^n$, enter:

sum 2**n|x=1~100