# PiSwift

> Approximates pi using Monte Carlo method with interactive visualizations and performance tracking. (iPhone/iPad app by Richard Loda.)

- Source: https://appshunter.io/ios/app/piswift/id1291794367 (this page in markdown: same URL + `.md`)
- Developer: [Richard Loda](https://appshunter.io/developer/1291794366)
- Category: Education
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings · 1 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 7 MB
- Languages: American English
- Released: 2017-10-03
- Data updated: 2026-06-10
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/piswift/id1291794367/reviews.md

## What is PiSwift?

PiSwift uses the Monte Carlo method to approximate the value of pi.

A circle inscribed in a square of area 1 has an area of pi x r2 = pi / 4. Thus the ratio of the number of random points landing in the circle to the number of total points in the square, times 4, approximates pi.

This app generates a total number of random points ranging over seven orders of magnitude. It enables the user to see the value of pi evolve through plots of pi, and delta, the percentage difference between the calculated pi value and the value of pi stored in the computer. It also presents a scatter plot of sampled points to aid in visualizing the process, and calculates how long it takes for your device to generate the random points and do the calculation.

It’s not the fastest, most accurate or most sophisticated method known to approximate pi, but it is fun to watch the value of pi “evolve” as more random points are used, and observe how few points are needed to come close to the actual value.

INSTRUCTIONS:

Load app, choose number of points with stepper, press Calculate Pi.
Main screen scatter plot presents 100 sampled points of equally spaced data (see below).
Press Graph button to observe the evolution of pi or delta (toggle) in graphical form.
Double tap gesture changes the origin of  the graph, pan moves the graph.
Pinch gesture at greater than 45 degrees scales the Y axis, and at less than 45 degrees scales the X axis (independently).
Stepper in Graph view allows for the independent scaling of delta (Y axis, to x200).

USAGE TIPS:

Start with a low number of points to initially see how long your iOS device takes to perform the calculation.
Use that number to predict the time required for a larger number of points (older devices take many minutes for upper limits).
Graph shows values of pi or delta after the sampling interval. If Log10 points = 2, pi or delta are calculated after every point. If Log10 points = 3, pi or delta are calculated every 10 points. If Log10 points = 4, it calculates values every 100 points, etc.
If you dislike your graph adjustments, toggling the Back/Graph button resets the graph to original values, without re-calculating pi.

## Key features

- Monte Carlo pi approximation
- Interactive scatter plot of points
- Evolutionary graphs of pi and delta
- Performance timing for calculations
- Adjustable number of random points
- Graph scaling and origin adjustment

## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/piswift/id1291794367/reviews.md

### 5/5 — Works well & can use large   of points

*2017-11-03, version 1.0*

Good app. Took my 5s phone about a half second to generate a million points and calculate pi. Pretty neat. Delta plot very useful for large  numbers of points. Support url has some interesting pi statistics for Monte Carlo method.

## Frequently asked questions about PiSwift

### How does PiSwift approximate pi?

PiSwift uses the Monte Carlo method. It generates random points within a square and calculates the ratio of points that fall within an inscribed circle. Multiplying this ratio by 4 approximates the value of pi.

### What kind of graphs does PiSwift offer?

PiSwift provides two main graphs: a scatter plot showing the sampled points and a graph that visualizes the evolution of the calculated pi value or delta (the percentage difference from the true value of pi) as more points are added.

### Can I customize the graphs in PiSwift?

Yes, you can adjust the graphs by double-tapping to change the origin, panning to move the graph, and using pinch gestures to scale the X and Y axes independently. The stepper in the graph view also allows for independent scaling of delta.

### How does the number of points affect the calculation in PiSwift?

The number of points directly influences the approximation's accuracy and the calculation time. More points generally lead to a more accurate approximation of pi but require more processing time on your device. You can select the number of points using a stepper.

### Does PiSwift show how long calculations take?

Yes, PiSwift calculates and displays how long it takes for your device to generate the random points and perform the pi calculation. This feature helps users understand device performance for computational tasks.

### Is PiSwift suitable for younger learners?

PiSwift has an age rating of 4+, making it accessible for a wide range of users. Its visual approach to a mathematical concept can be engaging for students learning about approximations and simulations.

### How often is PiSwift updated?

The latest version of PiSwift is 1.2, which was last updated on March 20, 2021. This indicates a moderate update frequency for the application.

### Does PiSwift have ads?

No, PiSwift does not contain advertisements. It is a free application that focuses on providing an educational experience without interruptions from ads.

## Version history (last 3 releases)

### 1.2 — 2021-03-20

Fixed a bug in graphics routine.

### 1.1 — 2020-12-05

Minor upgrades and bug fix.

### 1.0 — 2017-10-03

No release notes.

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## More apps by Richard Loda

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All apps by Richard Loda: https://appshunter.io/developer/1291794366

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*