Drawing chart using Core Plot in iOS

Core Plot

• Core Plot is one of the great framework to create chart in iOS. It has awesome feature to draw smooth and nice chart. Here is some overview about core plot.

Introduction:

Core plot is a 2D plotting framework for iOS. We can draw many type of graph using core plot library. We can use core plot library for Mac OS X and iOS.

You can draw many type of graph using core plot. They are 

1. Multi Color Bar chart
2. Vertical bar chart
3. Curved scatter plot 
4. Math function plot 
5. Candlestick plot
6. OHLC (Open high low close chart) plot
7. Range plot
8. Donut chart
9. Pie chart
10. Real time plot

Structure:

• Layers: There is a CPTLayer class, which is a subclass of CALayer. CPTLayer class used to produce vector images, quality graphics and to support event handling. It is used to draw graphics on the screen.

• Graphs: This is main and central class of core plot. It is an abstract class and all classes derive from it. It works like a complete diagram which includes axes, labels, title and more than one plot.

• Plot area: CPTPlotArea class represents the plot area. It includes data plotting, axes, grid lines and too name a few.

• Plot Spaces: CPTPlotSpace class represents plot spaces. It has to implement methods for transforming from drawing coordinates to data coordinates. Here data coordinates are the points passed by array points and Drawing coordinates are the view point on the graph.

• Plots: Anything we draw on graph represents plot. There are various types of plotting like Line, Scatter, bar plot or histogram plot. A graph has multiple plots. So every plot has a set of number of plots point and set of data. CPTPlot class is an abstract class of all plotting class like CPTScatterPlot and CPTBarPlot.

• Axes: A basic graph has two axis x and y. CPTAxis class is used to represents data to the x and y-axis. CPTAxisSet is used to creates two axis x and y.

For more information about core plot example and framework, please visit this link,

https://github.com/core-plot/core-plot

https://github.com/core-plot/core-plot/wiki/High-Level-Design-Overview