The same plot in 14 other libraries — Python: Altair, Bokeh, lets-plot, Matplotlib, plotnine, Pygal, Seaborn; R: ggplot2; Julia: Makie.jl; JavaScript: Chart.js, D3.js, Apache ECharts, Highcharts, MUI X Charts. Compare all 15 side by side: NMR Spectrum (Nuclear Magnetic Resonance) in Python, R, Julia and JavaScript.
An NMR spectrum plots signal intensity versus chemical shift (in ppm) to reveal the electronic environment of atomic nuclei in a molecule. It is the primary analytical tool in organic chemistry for determining molecular structure, with peak positions indicating functional groups and splitting patterns (multiplets) revealing connectivity between neighboring atoms. The x-axis is conventionally reversed (high ppm on the left) and peaks appear as sharp signals rising from a baseline.
""" anyplot.ai
spectrum-nmr: NMR Spectrum (Nuclear Magnetic Resonance)
Library: plotly 6.7.0 | Python 3.13.13
Quality: 89/100 | Updated: 2026-06-03
"""
import os
import numpy as np
import plotly.graph_objects as go
# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"
INK_MUTED = "#6B6A63" if THEME == "light" else "#A8A79F"
GRID = "rgba(26,26,23,0.15)" if THEME == "light" else "rgba(240,239,232,0.15)"
# Imprint palette — first series always #009E73
IMPRINT_PALETTE = ["#009E73", "#C475FD", "#4467A3", "#BD8233", "#AE3030", "#2ABCCD", "#954477", "#99B314"]
BRAND = IMPRINT_PALETTE[0] # #009E73 — spectrum line
# Data — synthetic 1H NMR spectrum of ethanol
np.random.seed(42)
chemical_shift = np.linspace(-0.5, 5.0, 6000)
w = 0.012 # peak width (standard deviation)
# TMS reference peak at 0 ppm
intensity = 0.4 * np.exp(-((chemical_shift - 0.0) ** 2) / (2 * w**2))
# CH3 triplet near 1.2 ppm (1:2:1 ratio)
intensity += 0.55 * np.exp(-((chemical_shift - 1.11) ** 2) / (2 * w**2))
intensity += 1.10 * np.exp(-((chemical_shift - 1.18) ** 2) / (2 * w**2))
intensity += 0.55 * np.exp(-((chemical_shift - 1.25) ** 2) / (2 * w**2))
# OH singlet near 2.6 ppm
intensity += 0.35 * np.exp(-((chemical_shift - 2.61) ** 2) / (2 * 0.015**2))
# CH2 quartet near 3.7 ppm (1:3:3:1 ratio)
intensity += 0.25 * np.exp(-((chemical_shift - 3.585) ** 2) / (2 * w**2))
intensity += 0.75 * np.exp(-((chemical_shift - 3.655) ** 2) / (2 * w**2))
intensity += 0.75 * np.exp(-((chemical_shift - 3.725) ** 2) / (2 * w**2))
intensity += 0.25 * np.exp(-((chemical_shift - 3.795) ** 2) / (2 * w**2))
# Subtle baseline noise
intensity += np.random.normal(0, 0.003, len(chemical_shift))
intensity = np.clip(intensity, 0, None)
# Imprint palette assignment per peak group
peak_colors = {
"TMS": IMPRINT_PALETTE[0], # brand green
"CH₃": IMPRINT_PALETTE[2], # blue
"OH": IMPRINT_PALETTE[1], # lavender
"CH₂": IMPRINT_PALETTE[3], # ochre
}
def hex_to_rgba(hex_color, alpha):
r = int(hex_color[1:3], 16)
g = int(hex_color[3:5], 16)
b = int(hex_color[5:7], 16)
return f"rgba({r},{g},{b},{alpha})"
# Plot
fig = go.Figure()
# Main spectrum trace — Imprint brand green
fill_alpha = 0.07 if THEME == "light" else 0.12
fig.add_trace(
go.Scatter(
x=chemical_shift,
y=intensity,
mode="lines",
line={"color": BRAND, "width": 2.5, "shape": "spline"},
fill="tozeroy",
fillcolor=hex_to_rgba(BRAND, fill_alpha),
hovertemplate="δ %{x:.2f} ppm<br>Intensity: %{y:.3f}<extra></extra>",
showlegend=False,
)
)
# Region shadings — Imprint palette, slightly higher opacity on dark for perceptibility
region_alpha = 0.07 if THEME == "light" else 0.13
peak_regions = [
{"x0": -0.05, "x1": 0.05, "color": peak_colors["TMS"]},
{"x0": 1.05, "x1": 1.32, "color": peak_colors["CH₃"]},
{"x0": 2.53, "x1": 2.69, "color": peak_colors["OH"]},
{"x0": 3.55, "x1": 3.84, "color": peak_colors["CH₂"]},
]
shapes = [
{
"type": "rect",
"xref": "x",
"yref": "paper",
"x0": region["x0"],
"x1": region["x1"],
"y0": 0,
"y1": 1,
"fillcolor": hex_to_rgba(region["color"], region_alpha),
"line": {"width": 0},
"layer": "below",
}
for region in peak_regions
]
# Annotations — color-coded, theme-adaptive text and backgrounds
annotations_data = [
{"x": 0.0, "y": 0.42, "text": "<b>TMS</b><br><i>δ</i> 0.00", "key": "TMS", "ay": -55},
{"x": 1.18, "y": 1.13, "text": "<b>CH₃</b> triplet<br><i>δ</i> 1.18", "key": "CH₃", "ay": -50},
{"x": 2.61, "y": 0.38, "text": "<b>OH</b> singlet<br><i>δ</i> 2.61", "key": "OH", "ay": -55},
{"x": 3.69, "y": 0.78, "text": "<b>CH₂</b> quartet<br><i>δ</i> 3.69", "key": "CH₂", "ay": -50},
]
styled_annotations = [
{
"x": ann["x"],
"y": ann["y"],
"text": ann["text"],
"showarrow": True,
"arrowhead": 3,
"arrowsize": 1.2,
"arrowwidth": 2,
"arrowcolor": peak_colors[ann["key"]],
"font": {"size": 11, "color": INK, "family": "Arial, sans-serif"},
"ax": 0,
"ay": ann["ay"],
"bgcolor": ELEVATED_BG,
"bordercolor": peak_colors[ann["key"]],
"borderwidth": 1.5,
"borderpad": 4,
}
for ann in annotations_data
]
# Title — n=60 < 67 baseline, use default 16px
title_text = "Ethanol ¹H NMR · spectrum-nmr · python · plotly · anyplot.ai"
# Layout
fig.update_layout(
autosize=False,
paper_bgcolor=PAGE_BG,
plot_bgcolor=PAGE_BG,
font={"color": INK, "family": "Arial, sans-serif"},
title={
"text": title_text,
"font": {"size": 16, "color": INK, "family": "Arial, sans-serif"},
"x": 0.5,
"xanchor": "center",
},
xaxis={
"title": {"text": "Chemical Shift <i>δ</i> (ppm)", "font": {"size": 12, "color": INK}, "standoff": 12},
"tickfont": {"size": 10, "color": INK_SOFT},
"autorange": "reversed",
"range": [5.0, -0.5],
"dtick": 0.5,
"showgrid": False,
"zeroline": False,
"showline": True,
"linecolor": INK_SOFT,
"linewidth": 1.5,
"ticks": "outside",
"ticklen": 8,
"tickwidth": 1.5,
"tickcolor": INK_SOFT,
"minor": {"dtick": 0.1, "ticks": "outside", "ticklen": 4, "tickcolor": INK_MUTED},
"spikemode": "across",
"spikethickness": 1,
"spikecolor": INK_MUTED,
"spikedash": "dot",
},
yaxis={
"title": {"text": "Intensity (a.u.)", "font": {"size": 12, "color": INK}, "standoff": 8},
"tickfont": {"size": 10, "color": INK_SOFT},
"showgrid": True,
"gridcolor": GRID,
"gridwidth": 1,
"griddash": "dot",
"zeroline": True,
"zerolinecolor": INK_SOFT,
"zerolinewidth": 1.5,
"showline": True,
"linecolor": INK_SOFT,
"linewidth": 1.5,
"ticks": "outside",
"ticklen": 8,
"tickwidth": 1.5,
"tickcolor": INK_SOFT,
"rangemode": "tozero",
},
template=None,
annotations=styled_annotations,
shapes=shapes,
showlegend=False,
margin={"l": 80, "r": 40, "t": 80, "b": 60},
hoverlabel={"bgcolor": ELEVATED_BG, "bordercolor": BRAND, "font": {"size": 11, "color": INK}},
hovermode="x unified",
)
# Save — landscape 3200×1800
fig.write_image(f"plot-{THEME}.png", width=800, height=450, scale=4)
fig.write_html(f"plot-{THEME}.html", include_plotlyjs="cdn")
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/spectrum-nmr/plotly/code. Any spec id and library id listed in llms-full.txt fit the same URL shape; every URL below is complete and callable.
{
"spec_id": "spectrum-nmr",
"language": "python",
"library": "plotly",
"page": "https://anyplot.ai/spectrum-nmr/python/plotly",
"hub": "https://anyplot.ai/spectrum-nmr",
"code_json": "https://api.anyplot.ai/specs/spectrum-nmr/plotly/code",
"spec_json": "https://api.anyplot.ai/specs/spectrum-nmr",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/spectrum-nmr/python/plotly/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/spectrum-nmr/python/plotly/plot-dark.png",
"interactive_light_html": "https://storage.googleapis.com/anyplot-images/plots/spectrum-nmr/python/plotly/plot-light.html",
"interactive_dark_html": "https://storage.googleapis.com/anyplot-images/plots/spectrum-nmr/python/plotly/plot-dark.html",
"quality_score": 89.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of NMR Spectrum (Nuclear Magnetic Resonance) on anyplot.ai.