toggle and elseif in matlab

Try adding a variable doDisplay to toggle if the densities are displayed. Add this condition with an elseif block.

i do not understand what we are supposed to do in the above question(bold). this question is a part of futher practice in mathlab oramp. decision branching topic futher practice section in matworks course for basic matlab. how do i solve tha bove question

https://matlabacademy.mathworks.com/R2019b/portal.html?course=gettingstarted#chapter=13&lesson=2&section=1

[Misbah Rafi Farooqui]

write "doPlot>=1"

Answer 1

[Geoff Hayes]

Shivaani - I think that all the code is asking you to do is to add another variable called doDisplay and an elseif that would check if this variable is true. If so, then you would plot the densities. So there would be two ways to plot the data - either through the doPlot or with the doDisplay

if doPlot
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
elseif doDisplay
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)") 
else
    disp("The density of " + element ...
        + " is " + density)
end

You would need to declare and initialize the doDisplay variable too.

[Shivaani S]

Geoff Hayes, thanks a ton !

[Devendra Singh]

its not working properly dear Geoff Hayes only error( Are the densities displayed when doPlotis 0?)

[Geoff Hayes]

I'm not sure then...I added the above code and was able to proceed/pass. Are you sure that you have defined doDisplay?

[Elisa R]

This is what I did. I ran it numerous times. both doPlot and doDisplay have to be 0 in this scenario in order for the text to display instead of the plot.

doPlot = randi([0 1])
load datafile
density = data(:,1);
doDisplay = randi([0 1])
if doPlot == 1
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
elseif doDisplay == 1
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)") 
else
    disp("The density of " + element ...
        + " is " + density)
end

Answer 2

[Saif Alameri]

My interpretation to this practice is to create another variable (doDisplay) with random number (0 or 1) just like the (doPlot), then use it as a second condtion for (elseif):

doPlot = randi([0 1])
doDisplay=randi([0 1])

load datafile
density = data(:,1);

if doPlot == 1
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
elseif doDisplay == 1
    disp("The density of " + element + " is " + density)
end

When:

doPlot = 0 and doDisplay = 0, then nothing displaied

doPlot = 1 and doDisplay = 0, then plot displaied

doPlot = 0 and doDisplay = 1, then density displaied

doPlot = 1 and doDisplay = 1, then only plot displaied

The point of this practice is to explain that second condtion will executing only when it met it's condtion and first condtion is not.

[DGM]

I think this is the correct and most direct interpretation of the instructions. I can see why a person would be confused though, as it doesn't really make sense to use if/elseif for this. To me, it would be more sensible to do

if doPlot
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
end

if doDisplay
    disp("The density of " + element + " is " + density)
end

Otherwise, there's not really any point in using multiple flags to control the behavior. As much as I think it's better, this isn't what the instructions describe.

Answer 3

[Varot Pakavatsoontorn]

Hi, I think the instructor might mean the following:

doDisplay = 1-doPlot
if doPlot == 1
plot(density)
title("Sample Densities")
xticklabels(element)
ylabel("Density (g/cm^3)")
elseif doDisplay == 1
    disp("The density of " + element ...
    + " is " + density)
end

[Simone Silva]

Hi.

The instructor asks what hapenned when doPlot and doDisplay are both equal one or they both equal zero.

If we define doDisplay=1-doPlot, the cases above are not possible.

[Rik]

Comment posted as flag by ANAHITA SOLTANTOUYEH:

This is imo the best interpretation of the task at hand and a great solution.

Answer 4

[Kakasaheb Nikam]

a Simple trick that i follow is,

at beginning I also not understand,

so we read it thrice by breaking sentance.

apply simple common logic.

we understand it.

Answer 5

[Joanne Middour]

This is the way I did it because I was under the impression that they are asking us to do recursion here, but I may be wrong.

doDisplay = randi([0 1])
if doPlot == 1
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
elseif doDisplay == 1
    doPlot = 1
else
    disp("The density of " + element ...
        + " is " + density)
end

[ABINESH R]

they are also asking what happens when they both equal zero, or when only doDisplay equals one?What's the ans for this

Answer 6

[sai]

if doPlot == 1
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
elseif doDisplay
     disp("The density of " + element ...
    + " is " + density)
end

Answer 7

[kunku S M]

try this, i think it's the answer

doDisplay=randi([0 1])
if doPlot == 0
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
elseif doDisplay == 1
    disp("The density of " + element ...
        + " is " + density)
end

Answer 8

[Muhammad]

I have tried: Here we can test what happens when both are equal to 1 or zero or only doDisplay is equal to 1. Nothing happens when both are equal to zero. When both are equal to 1, graph is printed. When only doDisplay is 1, it displays the densities. But still seems to be tricky quetion.

doPlot = randi([0 1])
doDisplay = randi([0 1])
density = 
if doPlot == 1
    plot(density)
    title("Sample Densities")
    xticklabels(element)
    ylabel("Density (g/cm^3)")
elseif doDisplay ~= doPlot
    disp("The dinsity of " + element ...
        + " is " + density)
else
    doPlot
    doDisplay
end

doPlot = 1

doDisplay = 0

Unrecognized function or variable 'density'.

[Walter Roberson]

density = 

That line is not valid MATLAB syntax.