ASCEND/C2/Iterative-calculations-and-Plotting-Graphs/English
Tutorial 6: Iteration & Graph Plotting
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Slide number 1
Title slide |
Welcome to the tutorial on Iteration & Graph Plotting in ASCEND |
Show Slide 2 | In this tutorial,
We will learn how to
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Slide number 3
System Requirement |
Here I am using
Ubuntu Linux OS v. 12.04 ASCEND v. 0.9.8 |
Slide number 4
Pre-requisites |
To follow this tutorial, user must have basic knowledge of Linux and ASCEND.
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Slide number 5
Problem Statement |
Let's look at the problem statement.
where H denotes the height and D denotes the diameter of the vessel. The equations describing our system is: metal mass = metal density * wall vol |
Source Code in Text Editor | Let's look at the source code for this problem. |
Zoom in on the MODEL vessel and paremeters part of the code. | We have two models in our file.
The first model defines parameters that will be passed in the second model.
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Zoom out and show the entire MODEL vessel | After defining the parameters, we define the required variables and equations.
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Zoom in on the second MODEL vesselplot. | Now we write our second MODEL vesselplot to use previously defined parameters. |
Highlight the declaration of n_entries | We define the total number of data points that we want, by defining variable n_entries |
Highlight the declaration of H_to_D_ratio and metal_mass | Therafter, we declare two arrays H_to_D_ratio and metal_mass to store the required values. |
Highlight the FOR loop | Now,we start a FOR loop, using which we pass the parameters of previous model in a new array v. |
Highlight the FOR loop in METHOD values | Note that,we assign values to the previously defined array H_to_D_ratio under METHOD values and not in our MODEL. |
Open up ASCEND interface.Load the program and run it. | Before moving any further, let's run our program and see how it stores the values in arrays. |
Point to the type 'array' displayed on interface | As you can see, ASCEND clearly indicates that H_to_D_ratio, metal_mass and v are arrays. |
Click on 'H_to_D_ratio' arrow | To see different values stored in the array, we just click on the drop down menu. |
Click on 'v' arrow | Also, to see the values of the parameters passed to array v, we click on the arrow next to it. |
Source code in Text editor | Now, let's learn how to plot a graph between the values stored in the two arrays. |
Highlight REQUIRE "plot.a4l” | Firstly, we need to include plot.a4l library in our model to use the plot function. |
Highlight massVSratio IS_A plt_plot_symbol | To plot a graph in ASCEND, we need to declare a variable of the type plt_plot_symbol. |
Highlight (CurveSet, Curves) | This declaration requires two parameters namely Curveset and Curves. |
Highlight the following lines:
CurveSet IS_A set OF symbol_constant; CurveSet :== ['test']; |
Curveset allows us to tag and identify each of the curves we plot. |
Highlight the following lines:
Curves['test'] IS_A plt_curve([1..n_entries], metal_mass,H_to_D_ratio) |
The second parameter Curves requires 3 parameters-
In our case, this set of integers is from 1to 20.
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Highlight the following lines:
massVSratio.title :='Metal mass of the walls vs H to D ratio for a thin-walled cylindrical vessel'; massVSratio.XLabel := 'H to D ratio'; massVSratio.YLabel := 'metal mass IN kg/m^3 |
We give title and label for our plot under the METHODS section. |
Open up ASCEND interface.Load the program and run it. | Let us now see how to get the required plot.
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Right-click on massVSratio and choose the plot option | We simply need to click on the mass vs ratio and choose the plot option. |
Maximise the plot window | This gives us the required plot, with the title and the labels that we mentioned in the code. |
Source code in Text editor | Let us now see what happens if we don't mention the plot title. |
Remove the massVSratio.tittle line from the source code and save it. | We remove the title line from our source code. |
Open up ASCEND interface.Load the program and run it. | We will re-compile the program. |
Maximise the plot window | We can clearly see that ASCEND titles the plot as 'undefined'. |
Slide number 6
Summary |
This brings us to the end of this tutorial. Let’s summarize. |
Click to bring up the bullets | In this tutorial, we have learnt to
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Slide Number 7
Assignment |
As an assignment, change the size of array to 40 and re-attempt this problem. |
Slide Number 8
About slide |
Watch the video available at
http://spoken-tutorial.org/What_is_a_Spoken_Tutorial It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it |
Slide number 9
About slide |
The Spoken Tutorial Project Team:
Conducts workshops using spoken tutorials Gives certificates to those who pass an online test For more details, please write to contact@spoken-tutorial.org
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Slide number 10
Acknowledgment |
Spoken Tutorial Project is a part of the Talk to a Teacher project
It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at[1]http://spoken-tutorial.org/NMEICT-Intro
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Slide number 11
Thank you slide |
This is Tarun Gangwar from IIT Bombay signing off. Thank you for joining. |