Complex Number App - graphing with core-plot, power-plot or else?

Question

I'm coding iOS app that will explain complex numbers to the user. Complex numbers can be displayed in Cartesian coordinates and that's what I want to do; print one or more vectors on the screen.

I am looking for the easiest way to print 3 vectors into a coordinate system that will adjust itself to the vector-size (if x-coord is > y-coord adjust both axis to x-coord and vice versa).

I tried using Core Plot, which I think is way too multifunctional for my purpose. Right now I am working with PowerPlot and my coordinate system looks okay already, but I still encounter some problems (x- and y-axis are set to the x and y values which results in a 45 degree angled line, no matter the user input).

The functionality of the examples in CorePlot and PowerPlot don't seem to meet my needs.

My last two approaches were using HTML and a web view, and doing it all myself with Quartz (not the simple way...)

Do you have any advice how to do this the simple way, as it is a simple problem, I guess?

Answer 1

If you're not wanting to do much actual graphing and plotting, then using Core Plot or similar sounds like overkill to me. The extra bloat of adding coreplot to your project, not to mention the time taken for you to understand how to use it, might not be worth it for some simple graphics.

Quartz is well equipped for the job of showing a few vectors on the screen, assuming you're not interested in fancy 3D graphics. There are plenty of tutorials and examples of using Core Graphics (AKA Quartz) to draw lines etc. If you're going the Quartz route, perhaps get some simple line drawing going in Quartz, then ask more questions if you need help with the maths aspect of it.

The typical technique used when rendering with Quartz is to override drawRect in a subclass of UIView and place calls to Core Graphics drawing functions in there.

A decent question and example of Quartz line drawing is here:

How do I draw a line on the iPhone?

Answer 2

If you aren't adverse to using Google Chart Image you can load reasonably complex data sets in a simple manner by calling the appropriate URL and then putting the image in a UIImageView. It takes very little code: here is a blog post explanation with sample code.

The limitations are

• length of the data set is restricted by the max URL length you can request from Google (2048 characters, with encoding is large), though I've plotted with 120 data points in 4 series.
• a net connection is required (at least to get the initial chart)
• and perhaps the biggest problem, API is deprecated and will be discontinued in 2015 at some point. You would then have to switch to the UIWebView/Javascript Google Chart API implementation...

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Sample image: