BASIC_CHART

Overview

The BASIC_CHART function generates a simple matplotlib chart (line or bar) from provided numeric data and returns the chart as a PNG image encoded as a base64 string. This allows embedding charts directly in Excel or web dashboards. The function uses the matplotlib library (documentation ).

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

Usage

To use the function in Excel:


=BASIC_CHART(data, [chart_type], [title], [xlabel], [ylabel])

data (2D list, required): Numeric data for the chart (rows/columns).
chart_type (string, optional, default=“line”): ‘line’ or ‘bar’.
title (string, optional): Chart title.
xlabel (string, optional): X-axis label.
ylabel (string, optional): Y-axis label.

The function returns a PNG image as a base64 string (starting with data:image/png;base64, ...) for embedding. If an error occurs, a string error message is returned.

Examples

Example 1: Simple Line Chart

This example creates a line chart for a growth curve.

X	Y
1	2
2	4
3	8
4	16

In Excel:


=BASIC_CHART({1,2;2,4;3,8;4,16}, "line", "Growth Curve", "X Axis", "Y Axis")

Expected output: a string starting with data:image/png;base64, (the chart image).

Example 2: Bar Chart

Category	Value
A	10
B	20
C	15

In Excel:


=BASIC_CHART({"A",10;"B",20;"C",15}, "bar", "Category Values", "Category", "Value")

Expected output: a string starting with data:image/png;base64, (the chart image).

Python Code


options = {"insert_only":True}
 
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import numpy as np
import io
import base64
 
def basic_chart(data, chart_type='line', title=None, xlabel=None, ylabel=None):
    """
    Generates a matplotlib chart from 2D numeric data and returns a PNG image as a base64 string.
    Args:
        data: 2D list of numbers (Excel range or similar)
        chart_type: 'line' or 'bar' (default: 'line')
        title: Chart title (optional)
        xlabel: X-axis label (optional)
        ylabel: Y-axis label (optional)
    Returns:
        PNG image as base64 string starting with 'data:image/png;base64,' or error message string
    
    This example function is provided as-is without any representation of accuracy.
    """
    if not isinstance(data, list) or not data or not isinstance(data[0], list):
        return "Error: Input data must be a 2D list."
    try:
        arr = np.array(data, dtype=float)
    except Exception:
        return "Error: Data must be numeric."
    if arr.ndim != 2 or arr.shape[1] < 2:
        return "Error: Data must have at least two columns (X and Y)."
    x = arr[:, 0]
    y = arr[:, 1]
    plt.figure(figsize=(6, 4))
    if chart_type == 'bar':
        plt.bar(x, y)
    else:
        plt.plot(x, y, marker='o')
    if title:
        plt.title(title)
    if xlabel:
        plt.xlabel(xlabel)
    if ylabel:
        plt.ylabel(ylabel)
    plt.tight_layout()
    buf = io.BytesIO()
    plt.savefig(buf, format='png')
    plt.close()
    buf.seek(0)
    img_bytes = buf.read()
    img_b64 = base64.b64encode(img_bytes).decode('utf-8')
    return f"data:image/png;base64,{img_b64}"

Live Notebook

Edit this function in a live notebook .