which type of graph is suitable to plot dynamic data?

[hmshwe]

Thank you Bob_ Schor for the reply.
* Continuously sampled data is being recorded in one program's file.I'm writing another program which reads the running file and plots the graph.
* I want to retrieve the running file and plot the same on graph in my program.

If i use graph,I'm not able to see dynamic plot.

If i use chart,i can get only present readings.previous values l slide to left side.Actually I want to plot both previous values and present running values at the same time.

Please anybody do suggest how to increase chart memory size.

[crabman]

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@hmshwe wrote:

* Continuously sampled data is being recorded in one program's file.I'm writing another program which reads the running file and plots the graph.

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I'm not sure if you might get some troule if two applications try to access one file at the same time. Can you prvent concurrent access?

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@hmshwe wrote:

* I want to retrieve the running file and plot the same on graph in my program.

.Actually I want to plot both previous values and present running values

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How are the values stored in your file? Only X and Y value of the last sample? The last n samples? or all samples until now?

Best regards

[hmshwe]

* I will take running file only in read mode.

*Values are stored in columns.It contains all samples until now,and data goes on increasing.

[hmshwe]

* File is retrieved in read mode only.So,no trouble in accessing the file.

*Values are stored in two columns.

2017-09-04/18:46:03  12.112465
2017-09-04/18:46:04  15.134372
2017-09-04/18:46:05  18.153353
2017-09-04/18:46:06  22.172334
2017-09-04/18:46:07  27.194242

[crabman]

So if you just read the file and plot all values in a graph you will have what you want.

[hmshwe]

If i use graph,i'm not able to plot dynamic data.

If i use chart,plot slides towards left and disappears as new data arrives.

is there any way to increase chart history length?

is it possible to select required portion of plot and enlarge it?

[crabman]

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@hmshwe wrote:

If i use graph,i'm not able to plot dynamic data.

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Just to clarify this:
1. You read the file the first time and get let's say 100 values. You plot them in your graph -> your graph shows 100 data points.

2. You read the file again. Now it contains 200 values. You plot them in your graph -> your graph shows 200 data points.

3. You read the file again. Now it contains 300 values...

and so on

Isn't this exactly what you want. Or what do you mean by "dynamic data"?

[crossrulz]

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hmshwe wrote:

* I want to retrieve the running file and plot the same on graph in my program.

If i use graph,I'm not able to see dynamic plot.

If i use chart,i can get only present readings.previous values l slide to left side.Actually I want to plot both previous values and present running values at the same time.

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A file is not a good way to transfer data between applications.  This is especially true if the file is  constantly being overwritten.   You can easily miss data that way.  Use a TCP connection or a Network Stream to pass the data.