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pl-matrix-latex element

Displays a scalar or 2D numpy array of numbers in LaTeX using mathjax.

Sample element

Screenshot of the pl-matrix-latex element

question.html
$$C = <pl-matrix-latex params-name="matrixC"></pl-matrix-latex>$$
server.py
import prairielearn as pl
import numpy as np

def generate(data):

    # Construct a matrix
    mat = np.matrix("1 2; 3 4")

    # Export matrix to be displayed in question.html
    data["params"]["matrixC"] = pl.to_json(mat)

Customizations

Attribute Type Default Description
digits integer 2 Number of digits to display according to the choice of presentation-type
params-name string — Name of variable in data["params"] to display.
presentation-type string "f" Number display format. If presentation-type is "sigfig", each number is formatted using the to_precision module to digits significant figures. Otherwise, each number is formatted as '{:.{digits}{presentation-type}}'.

Details

Depending on whether data["params"] contains either a scalar or 2D numpy array of numbers, one of the following will be returned.

  • scalar
    • a string containing the scalar not wrapped in brackets.
  • numpy 2D array
    • a string formatted using the bmatrix LaTeX style.

Sample LaTeX formatting:

\begin{bmatrix} ... & ... \\ ... & ... \end{bmatrix}

As an example, consider the need to display the following matrix operations:

x = [A][b] + [c]

In this case, we would write:

question.html
${\bf x} = <pl-matrix-latex params-name="A" digits="1"></pl-matrix-latex>
<pl-matrix-latex params-name="b" digits="1"></pl-matrix-latex>
+ <pl-matrix-latex params-name="c" digits="1"></pl-matrix-latex>$

Example implementations

See also