ipycalc 1.0.0

Clean looking engineering calculations for IPython

ipycalc

Simple Engineering Calculations in Jupyter

Turn the contents of a Jupyter cell into a formatted calculation by following the steps below:

1. Install ipycalc using pip install ipycalc
2. Use from ipycalc import calc to bring ipycalc into your notebook's namespace.
3. Use %%calc as the first line of a cell to indicate that you want to run ipycalc on the contents of a cell.

The basic calculation syntax is:

Variable Description: variable_name = python_expression -> result_decimal_places*result_unit # Reference Text

Here's a simple example that calculates the flexural strength of a concrete beam:

Key components of the ipycalc syntax are:

• : (required) The description must come before this character.
• = (optional) Used to assign a python expression to a variable name. Omit this if you simply want to reprint a previously defined variable.
• -> (optional) Separates the python expression from the results formatting rules.
• * (optional) Indicate the number of decimals you want to see in the result to the left of the *, and the units you want to see in the result to the right.
• # (optional) Indicates reference text to the side of the calculation - handy for equation references or code references.

Here are a few useful things to keep in mind when using ipycalc:

• Subscripts can be added by using the _ character to indicate the start of a subscript.
• Greek characters included in the python_expression can just be written out (e.g. epsilon). To include greek characters in the Variable Description or the Reference Text, you can use Jupyter's Markdown Latex tags (e.g. $\epsilon$). Note that the greek character psi is ambiguous with the unit psi (pounds per square inch), so for that character specifically you'll need to use \grpsi to tell ipycalc you want the greek character rather than the unit.
• To stack fractions place the numerator and denominater in parentheses: (num)/(denom) yields $\dfrac{num}{denom}$.
• if statements and else statements are available using python's inline if statement (terniary) notation.
• Square roots can be displayed using sqrt.
• Prime characters can be displayed using ^prime.
• If text gets to lengthy to fit on one line, you can add \\ to force a line break anywhere in a line. This can help your calculations fit within the page's print margins.
• ipycalc assists you with printing your notebooks. It has a built in nbconvert template called ipycalc that works just like the webpdf template, except it fixes the the bad margins in the webpdf template, and avoids page breaks right after headers. Any cells tagged with hide_cell will not be rendered. Any cells tagged with hide_input will only show the output upon printing. You can select it from the file menu via "File -> Save and Export Notebook As... -> Ipycalc"

Sharing Variables Between Notebooks

ipycalc can save variables from one notebook and import them into another. This is useful when a project spans multiple notebooks (e.g. a loads notebook feeding into a beam design notebook).

Saving variables:

from ipycalc import save_vars
save_vars('my_notebook.ipynb')

This writes all user-defined variables — including pint quantities with units — to a sidecar file at .ipycalc_vars/my_notebook.json in the same directory as the notebook. The notebook file itself is never modified.

Importing variables:

from ipycalc import import_vars
import_vars('my_notebook.ipynb')           # import all saved variables
import_vars('my_notebook.ipynb', 'P', 'L') # import specific variables only

Both functions are also available directly inside a %%calc cell without any import statement.

Variables are saved and loaded by filename only. Both notebooks must be in the same working directory.

IPycalc is still in development. There could be bugs, so be cautious and validate the answers it gives you. A special thanks to @connorferster for his project handcalcs which inspired this project. A link to handcalcs is here: https://github.com/connorferster/handcalcs.