HI All,
Is there any way to draw a 2d graph of ECG (in wave form) in iphone .I am getting a large anount of data in couple of seconds i mean the gap will be of just 1 Secs.then is there any way to draw the graph in iphone or any library (IN c or c++) by which i can use it and it draw a live graph of any heart beat analysis and looks alike a live video.
Thanks
Balraj.
Apple's Accelerometer example app (available on their iOS developer site, and with full source code) shows how to draw a 2D graph animated several times a second.
In addition to the Accelerometer sample that hotpaw2 points to, which is reasonably performant when it comes to graphing realtime data, there is the Core Plot graphing framework. Core Plot can give you a drop-in component with more options when it comes to formatting your graphs, but it may not be the fastest for displaying many data points that change rapidly on the iPhone.
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In android we have simple methods to load /preview camera and calculate mean colour of a of a predefined region and display dynamically.
Is it possible to do so in matlab?
I believe it is possible. This post closely related to your question (on images) you can find many tools for videos
caculate the mean of the region of interest
I am developing a code to display Spectrograph on iOS devices.I have the FFT data with me how to I plot the Spectograph with the FFT data.
You can refer MIM-Library, it may help you, it have some good charts in each category.
MIM-Library's Wall chart may fulfill your need.
I'm new to this core-plot framework and trying to draw a line graph based on X and Y acceleration. I can already get my X and Y values and have successfully added core-plot in my project. I'm quite lost on how to start this, so basically, I will have X and Y values and how do I plot this using core-plot? any help is suggested. Thanks!
Maybe my answer is a little bit off topic, as it's not using core-plot, but did you look at the "AccelerometerGraph" sample app provided with Xcode?
It provides a nice plot which is dynamically updated while new accelerometer events are registered. The great of this sample is the way CoreAnimation has been used to "speed-up" Quartz2D. And you get all of this using system framework only and no third party code (apart your adaptation of Apple's one).
Look at the Core Plot examples to see how to set up a basic graph. You'll want to use a scatter plot. Call -reloadData on the plot whenever you have new data to display. If only some of the data points change on each frame, you can use the following methods to do a partial update:
-(void)reloadDataInIndexRange:(NSRange)indexRange;
-(void)insertDataAtIndex:(NSUInteger)index
numberOfRecords:(NSUInteger)numberOfRecords;
-(void)deleteDataInIndexRange:(NSRange)indexRange;
The Real Time Plot in the Plot Gallery example app shows one way to use these methods.
I'm trying to graph large amounts of data, say around a million data points in a line graph. I've tried CorePlot, but it is somewhat lacking in speed. It couldn't even graph 30,000 points with any sort of usable rendering speed (less than 1 fps). s7graphview is somewhat similar to CorePlot but with less features. I put together a simple OpenGL ES project and graphed 1,000,000 points and it rendered at around 10 fps, which is a very usable speed for manipulating a graph. My question is this, are there any purely OpenGL ES based graphing libraries for the iPhone? If not, are there any open source OpenGL based ones I could potentially port to the iPhone? I'd rather not resort to writing my own graphing library unless absolutely necessary.
Edit:
Ok, since there aren't any takers, would anyone be willing to work together with me to make an Open Source OpenGL ES graphing library?
Update:
I've finished my OpenGL graphing library. It can graph 1,400,000 points at 10 fps with multiple lines and multiple scales attached to those lines, with dynamic resizing and it is a self contained control that can be dropped onto any window/view. Much better than CorePlot's 10,000 points at 10 fps.
Can someone give me some good tutorials on Creating a 2D plot on IPhone given a variable number of x,y coordinates?
If you're looking for something beyond just plotting the points, check out the open source Core Plot framework for Mac and iPhone. It's still a young project, but it can handle a scatter plot (with or without lines between the points) along with labeled axes just fine. There are a number of example programs included with the framework that demonstrate some of its capabilities.
You can do this with the CGContextAddLineToPoint method.
http://developer.apple.com/iphone/library/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_paths/dq_paths.html#//apple_ref/doc/uid/TP30001066-CH211