NZGrapher

Need Help?
Need help getting started? Watching these videos is a great place to start.

Want to know more? Information on the graphs and datasets, as well as video tutorials are over on the NZGrapher Info Site.

Something not working or have an idea to make NZGrapher better... please let me know.

Cost
NZGrapher is free for non-commercial individual use, you can however make a donation.

Schools are required to subscribe. I'm not asking much (50c or $1 per annum, per student, using NZGrapher), this just helps cover my costs for running NZGrapher. Commercial users are also required to pay. Please visit the invoice creator for details.

Any questions about this please get in touch.

By pressing the button below you are acknowledging that NZGrapher uses cookies, and if you acting on behalf of a school, you are agreeing to the costs associated... if you're not happy with this don't use this website. (Privacy Statement)

New in this version of NZGrapher (20260331)

Full changes can be seen by changing the graph type to 'Change Log'.

The version of NZGrapher you are using is hosted on my server.

NZGrapher uses third party libraries, click here to see the licences.

Advanced Tools

This section allows you to do things that aren't built into the main interface of NZGrapher, but may be useful to some users.
Please use this section with caution, as using your eyes as to what you can see in the graph is almost always better than just using the numbers.

To access the output of these you need to open the developer console. To do this on Chrome press the following key combinations.

Windows and Linux: Ctrl + Shift + J
Mac OS: Cmd + Opt + J

Scatter Graphs:
After drawing a scatter graph, the developer console will show all the different models including equations and r² values.

Time Series:
After drawing a re-composition graph press the button below to show the relative makeup of the different components. Note: this takes all values, including extreme values to produce these percentages.

View Components

Sampling Variability

This section lets you re-sample the same data while looking at a graph to see what happens when you take repeated samples.
This is really useful for teaching sampling variability.
You can see a video tutorial on how to use this here.

Sample With:

Fill Numbers (Re)Sample Animate (Slow) Animate (Fast) Stop Reset Data

Often it is useful to fix the axis when looking at scatter graphs and or dot plots.

Lock Axis Values Reset More Options

View Group(s)

This section lets you look at a single group inside a cateogry.

Category to Fiter On:

Select All Select None Reset Data Close Without Resetting

Often it is useful to fix the axis when looking at scatter graphs and or dot plots.

Lock Axis Values Reset More Options

Re-Randomisation Teaching Tool

This section lets you manually step through a creating re-randomisation distribution.
This is really useful for teaching how re-randomisation and the randomisation test work.
You can see a video tutorial on how to use this here.

Re-randomisation works by taking the sample, and randomly assigning each of the data points to one of the groups in the same proportion as the sample. It then works out the median or mean for each group and plots the difference between them on the graph below. It does this 1000 times and then works out the proportion that are equal or greater than the sample difference.

Do ONE re-randomisation and plot on graph:

Slow Fast

Step through remaining 1000 re-randomisations:

Slow Medium Fast

Other Controls:

Pause Reset

Bootstrap Confidence Interval Teaching Tool

This section lets you manually step through creating a bootstrap confidence interval.
This is really useful for teaching bootstrapping.
You can see a video tutorial on how to use this here.

Bootstrapping works by taking the sample, and randomly choosing as many points as in the original sample from the original sample, using replacement. This means that each point can potentially be chosen multiple times, or not at all. It then works out the median or mean for each group and plots the difference between them on the graph below. It does this 1000 times and shows the interval for the middle 95% (or 950 bootstrap samples).

Do ONE bootstrap sample and plot on graph:

Slow Fast

Step through remaining 1000 bootstrap samples:

Slow Medium Fast

Other Controls:

Pause Reset

Bootstrapping Single Variable Teaching Tool

This section lets you manually step through creating a bootstrap of a single variable.
This is really useful for teaching bootstrapping.
You can see a video tutorial on how to use this here.

Bootstrapping works by taking the sample, and randomly choosing as many points as in the original sample from the original sample, using replacement. This means that each point can potentially be chosen multiple times, or not at all. It then works out the median or mean for this new sample and plots it the graph below. It does this 1000 times and shows the interval for the middle 95% (or 950 bootstrap samples).

Find the bootstrap:

Do ONE bootstrap sample and plot on graph:

Slow Fast

Step through remaining 1000 bootstrap samples:

Slow Medium Fast

Other Controls:

Pause Reset

CI Coverage Teaching Tool

This section lets you view confidence interval coverage for a fixed sample size from a population.
This is really useful for teaching confidence intervals.
You can see a video tutorial on how to use this here.

You can set the sample size and the type of confidence interval you want to view. You can then do as many samples as you would like, seeing how many of them create a confidence interval that includes the population value.
You can adjust the sample size to see how it affects the coverage of the confidence interval.

Sample size:
CI Type:

One Slow Medium Fast

Other Controls:

Pause Reset

Simulation Model Teaching Tool

This section lets you view a simulation model and compare it to your data.
This is really useful for teaching random variation and looking at chance experiments.
You can see a video tutorial on how to use this here.

Data Type

This allows you to adjust the graph between a bar chart or a histogram, and alters the types of distributions available.

Simulated Distribution

This alters the distrubtion used to perform the simulation.

Description
Based on your selections above we will draw a of the original data.
This data has data points.
We will simulate with data points and show this in light grey.
We will do up to 1000 simulations and show the results in the graph.

Step through remaining 1000 simulations:

One Slow Medium Fast

Other Controls

Pause Reset

Event Recorder

Events

Count of: (type outcome you want to count)
Count of: (type another outcome you want to count)
Sum (only works if outcomes are numeric)
Unique Outcomes

Event Recorder

Events

Under data you can upload your own file, or paste in a table.			Up here you can choose the folder you are wanting if your school has one set up (press enter after typing it in) or select the dataset from the folder. There are lots of good ones loaded in, or you can load your own in the top left.

This left hand area displays your data (including the id on the left). You can add or delete rows as well as edit the data just by clicking and typing on it. To save the changes click the save changes in the menu.	Okay, I got it. Hide this overlay.	This area displays your graph.

Down here you can choose the x-variable and the y-variables as well as the type of graph you want to draw.		Down here you can change the options for the graph, including the titles and if the point labels are shown.

variable 1:		Graph Type:
variable 2:		Colour by:
variable 3:		Colour Scale:

Time Column:
Average / Sum:
Season Length:
Custom Period Length:
Custom Seasons Per Period:
Custom Seasons Start:	(must be equal to or before the first time)

Dot Plots (and Box and Whisker): For creating axis limits it pretend the ____ value is ____
Min:
Max:
For adjusting the size of the red summary statistics
Text Size:
Smoothing Power:
For adjusting the smoothness on violin and shape outline graphs. Larger number is more smooth.

Scatter Graphs: For creating axis limits it pretend the ____ value is ____
Min X:
Max X:
Min Y:
Max Y:
Rename X on Equations to:
Rename Y on Equations to:

Time Series Graphs: For creating axis limits it pretend the ____ value is ____
Min X:
Max X:
Min Y:
Max Y: