TRIPLOT

Excel Usage

=TRIPLOT(data, title, xlabel, ylabel, line_color, marker)
  • data (list[list], required): Input data with 2 columns (X, Y).
  • title (str, optional, default: null): Chart title.
  • xlabel (str, optional, default: null): Label for X-axis.
  • ylabel (str, optional, default: null): Label for Y-axis.
  • line_color (str, optional, default: “blue”): Color of the grid lines.
  • marker (str, optional, default: “none”): Marker style for points.

Returns (object): Matplotlib Figure object (standard Python) or base64 encoded PNG string (Pyodide).

Example 1: Simple triangular grid lines

Inputs:

data title
0 0 Triangular Grid
1 0
0 1
1 1
0.5 0.5

Excel formula:

=TRIPLOT({0,0;1,0;0,1;1,1;0.5,0.5}, "Triangular Grid")

Expected output:

"chart"

Example 2: Grid lines with markers

Inputs:

data marker line_color
0 0 o red
1 0
0.5 0.866

Excel formula:

=TRIPLOT({0,0;1,0;0.5,0.866}, "o", "red")

Expected output:

"chart"

Example 3: Grid lines with square markers

Inputs:

data marker line_color
0 0 s green
2 0
1 2

Excel formula:

=TRIPLOT({0,0;2,0;1,2}, "s", "green")

Expected output:

"chart"

Example 4: Simple black grid lines

Inputs:

data line_color
0 0 black
1 1
1 0

Excel formula:

=TRIPLOT({0,0;1,1;1,0}, "black")

Expected output:

"chart"

Python Code

import sys
import matplotlib
IS_PYODIDE = sys.platform == "emscripten"
if IS_PYODIDE:
    matplotlib.use('Agg')
import matplotlib.pyplot as plt
import io
import base64
import numpy as np

def triplot(data, title=None, xlabel=None, ylabel=None, line_color='blue', marker='none'):
    """
    Draw an unstructured triangular grid as lines and/or markers.

    See: https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.triplot.html

    This example function is provided as-is without any representation of accuracy.

    Args:
        data (list[list]): Input data with 2 columns (X, Y).
        title (str, optional): Chart title. Default is None.
        xlabel (str, optional): Label for X-axis. Default is None.
        ylabel (str, optional): Label for Y-axis. Default is None.
        line_color (str, optional): Color of the grid lines. Valid options: Blue, Green, Red, Black. Default is 'blue'.
        marker (str, optional): Marker style for points. Valid options: None, Point, Pixel, Circle, Square, Triangle Down, Triangle Up. Default is 'none'.

    Returns:
        object: Matplotlib Figure object (standard Python) or base64 encoded PNG string (Pyodide).
    """
    def to2d(x):
        return [[x]] if not isinstance(x, list) else x

    try:
        data = to2d(data)
        if not isinstance(data, list) or not data or not isinstance(data[0], list):
            return "Error: Input data must be a 2D list."

        # Convert to numpy array
        try:
            arr = np.array(data, dtype=float)
        except Exception:
            return "Error: Data must be numeric."

        if arr.shape[1] < 2:
            return "Error: Data must have at least 2 columns (X, Y)."

        # Extract coordinates
        x, y = arr[:, 0], arr[:, 1]

        # Create figure
        fig, ax = plt.subplots(figsize=(8, 6))

        # Plot triplot
        ax.triplot(x, y, color=line_color, marker=marker if marker else None)

        # Set labels and title
        if title:
            ax.set_title(title)
        if xlabel:
            ax.set_xlabel(xlabel)
        if ylabel:
            ax.set_ylabel(ylabel)

        plt.tight_layout()

        if IS_PYODIDE:
            buf = io.BytesIO()
            plt.savefig(buf, format='png', dpi=100, bbox_inches='tight')
            plt.close(fig)
            buf.seek(0)
            img_bytes = buf.read()
            img_b64 = base64.b64encode(img_bytes).decode('utf-8')
            return f"data:image/png;base64,{img_b64}"
        else:
            return fig
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

Input data with 2 columns (X, Y).
Chart title.
Label for X-axis.
Label for Y-axis.
Color of the grid lines.
Marker style for points.