TRIPCOLOR

Excel Usage

=TRIPCOLOR(data, title, xlabel, ylabel, color_map)

data (list[list], required): Input data with 3 columns (X, Y, Z).
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.
color_map (str, optional, default: “viridis”): Color map for plot.

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

Example 1: Simple triangular pseudocolor

Inputs:

data			title
0	0	1	Triangular Pseudocolor
1	0	2
0	1	3
1	1	4
0.5	0.5	5

Excel formula:

=TRIPCOLOR({0,0,1;1,0,2;0,1,3;1,1,4;0.5,0.5,5}, "Triangular Pseudocolor")

Expected output:

"chart"

Example 2: Pseudocolor with magma map

Inputs:

data			color_map
0	0	1	magma
2	0	10
1	2	5

Excel formula:

=TRIPCOLOR({0,0,1;2,0,10;1,2,5}, "magma")

Expected output:

"chart"

Example 3: Pseudocolor with cividis map

Inputs:

data			color_map
0	0	1	cividis
1	1	5
2	0	2

Excel formula:

=TRIPCOLOR({0,0,1;1,1,5;2,0,2}, "cividis")

Expected output:

"chart"

Example 4: Pseudocolor with inferno map

Inputs:

data			color_map
0	0	5	inferno
1	0	1
0	1	10

Excel formula:

=TRIPCOLOR({0,0,5;1,0,1;0,1,10}, "inferno")

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 tripcolor(data, title=None, xlabel=None, ylabel=None, color_map='viridis'):
    """
    Create a pseudocolor plot of an unstructured triangular grid.

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

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

    Args:
        data (list[list]): Input data with 3 columns (X, Y, Z).
        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.
        color_map (str, optional): Color map for plot. Valid options: Viridis, Plasma, Inferno, Magma, Cividis. Default is 'viridis'.

    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] < 3:
            return "Error: Data must have at least 3 columns (X, Y, Z)."

        # Extract coordinates
        x, y, z = arr[:, 0], arr[:, 1], arr[:, 2]

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

        # Plot tripcolor
        ax.tripcolor(x, y, z, cmap=color_map)

        # 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

data *

Input data with 3 columns (X, Y, Z).

title

Chart title.

xlabel

Label for X-axis.

ylabel

Label for Y-axis.

color_map

Color map for plot.