What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
For two measurements that share an x variable but need independent y ranges, create a second Axes with ax.twinx(). If the right-hand scale is a conversion of the same measurement—for example, radians to degrees—use ax.secondary_yaxis() with forward and inverse conversion functions. When both series use the same unit and a comparable range, keep them on one y-axis.
Choose one y-axis, two independent axes, or a converted axis
| Situation | Use | Why |
|---|---|---|
| Both series measure comparable values in the same unit and range | One Axes | A shared y-scale makes direct comparison clear; a second scale is unnecessary. |
| Two independent measurements share x but have different units or ranges | Axes.twinx() |
It creates a second y-axis with its own scale while sharing the original x-axis. |
| The right axis expresses the same quantity in another unit | Axes.secondary_yaxis() |
An explicit conversion links the alternate scale to the original rather than treating it as an unrelated measurement. |
Matplotlib’s stable “Plots with different scales” example documents twinx() for independent scales, while its “Secondary Axis” example documents the conversion-based approach. The stable gallery result identified Matplotlib 3.11.2 at research time; consult the documentation for the version you use: Plots with different scales and Secondary Axis.
Plot independent quantities with twinx()
Call twinx() on the original Axes, then draw each series on the Axes whose y-scale describes it. The second Axes shares the x-axis and places its independent y-axis on the right.
import matplotlib.pyplot as plt
fig, ax1 = plt.subplots()
ax1.plot(x, y1, color="tab:red")
ax1.set_xlabel("time (s)")
ax1.set_ylabel("quantity 1", color="tab:red")
ax1.tick_params(axis="y", labelcolor="tab:red")
ax2 = ax1.twinx()
ax2.plot(x, y2, color="tab:blue")
ax2.set_ylabel("quantity 2", color="tab:blue")
ax2.tick_params(axis="y", labelcolor="tab:blue")
fig.tight_layout()
plt.show()Replace x, y1, and y2 with your data arrays. Give both y-axes meaningful labels, including units, and use distinct line colors that match their axis labels and tick labels. tight_layout() helps keep the right-side label from being clipped.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
What the two scales mean
The left and right axes are independent: each series is positioned according to its own y-scale. The twinned axis inherits the original Axes’ x-axis autoscale setting, but its y scale is separate. The Matplotlib API reference describes the shared-x behavior and notes that LinearLocator can be used when you need tick marks on the two y-axes to align: Axes.twinx API reference.
Show a converted unit with secondary_yaxis()
For a second display of the same underlying quantity, provide a forward conversion and its inverse. For example, if the primary axis is in radians and the secondary axis is in degrees, the functions should convert in both directions:
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
import numpy as np
forward = lambda radians: np.degrees(radians)
inverse = lambda degrees: np.radians(degrees)
secax = ax.secondary_yaxis(
"right",
functions=(forward, inverse),
)
secax.set_ylabel("angle (degrees)")Here, ax is the existing primary Axes, whose y-axis is in radians. The conversion functions must accept NumPy arrays. The API also accepts an invertible Transform instead of a pair of functions. Secondary-axis limits are derived from the parent Axes; setting limits on the secondary axis does not change them. See Matplotlib’s Secondary Axis example for the documented pattern.
Keep a dual-scale chart interpretable
- Label both quantities and units directly on their respective axes.
- Match each series’ color to its axis label and tick labels so readers can identify the scale to use.
- Do not imply that two independently scaled measurements are directly comparable just because their lines share a chart. Explain what each series measures and which axis maps to it.
- If two scales make the relationship hard to read, use separate, vertically aligned subplots with a shared x-axis instead. That is a design alternative, not a guarantee that one layout is universally clearer.
Independent scaling can make the lines appear to track each other even when their values are not directly comparable. Describe the measurement relationship rather than asking readers to infer it from the line shapes.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Align tick marks when that comparison matters
If corresponding tick positions on the left and right axes need to line up, Matplotlib’s Axes.twinx() reference points to using a locator such as LinearLocator. Use alignment only when it helps interpret the chart; the axes remain independent scales, not one shared measurement.
Quick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
