BARBS

Excel Usage

=BARBS(data, title, xlabel, ylabel, barb_color)

data (list[list], required): Input data with 4 columns (X, Y, U, V).
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.
barb_color (str, optional, default: “blue”): Color of the barbs.

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

Example 1: Simple wind barb field

Inputs:

data				title
1	1	10	0	Wind Barbs
1	2	20	5
2	1	5	10
2	2	15	15

Excel formula:

=BARBS({1,1,10,0;1,2,20,5;2,1,5,10;2,2,15,15}, "Wind Barbs")

Expected output:

"chart"

Example 2: Green wind barbs

Inputs:

data				barb_color
1	1	10	10	green
2	2	20	20

Excel formula:

=BARBS({1,1,10,10;2,2,20,20}, "green")

Expected output:

"chart"

Example 3: Red wind barbs with labels

Inputs:

data				barb_color	xlabel	ylabel
0	0	5	5	red	East	North
1	1	15	15

Excel formula:

=BARBS({0,0,5,5;1,1,15,15}, "red", "East", "North")

Expected output:

"chart"

Example 4: Black wind barbs

Inputs:

data				barb_color
0	0	30	0	black
0	1	0	30

Excel formula:

=BARBS({0,0,30,0;0,1,0,30}, "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 barbs(data, title=None, xlabel=None, ylabel=None, barb_color='blue'):
    """
    Plot a 2D field of wind barbs.

    See: https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.barbs.html

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

    Args:
        data (list[list]): Input data with 4 columns (X, Y, U, V).
        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.
        barb_color (str, optional): Color of the barbs. Valid options: Blue, Green, Red, Black. Default is 'blue'.

    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] < 4:
            return "Error: Data must have at least 4 columns (X, Y, U, V)."

        # Extract coordinates
        X, Y, U, V = arr[:, 0], arr[:, 1], arr[:, 2], arr[:, 3]

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

        # Plot barbs
        ax.barbs(X, Y, U, V, barbcolor=barb_color, flagcolor=barb_color)

        # 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 4 columns (X, Y, U, V).

title

Chart title.

xlabel

Label for X-axis.

ylabel

Label for Y-axis.

barb_color

Color of the barbs.