scatter and plot are not same?
Title
Question
I used scatter and plot command as per the exercise given. i plotted them in subplot to have comparison for the given data x=linspace(1,20,100) and y=5x<sup>3</sup>. I am getting exactly same plot. while in tutorial answer says 'NO'. why this is so?
Python-3.4.3 Other-Types-Of-Plots 07-08 min 10-20 sec
Answers:
<span class="textBox">To combine multiple plots in one graph, use the “hold on” command, such as:</span>
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<span class="textBox" style="white-space: pre;"> plot(1:10)</span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> hold </span><span class="textWrapper String" style="color: rgb(160, 32, 240);">on </span></span>
<span class="textBox" style="white-space: pre;"> plot(11:20)</span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> hold </span><span class="textWrapper String" style="color: rgb(160, 32, 240);">off</span></span>
<span class="textBox" style="white-space: pre;">snr=0:1:15;</span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper Keyword" style="color: rgb(0, 0, 255);">for </span><span class="textWrapper">ii=1:length(snr)</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> x=randint(1,100000); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Generating bits</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> y=pskmod(x,2); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Generating BPSK modulated data</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> ynoisy=awgn(y,snr(ii)); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Adding AWGN noise to data</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> z=pskdemod(ynoisy,2); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Demodulating</span></span>
<span class="textBox" style="white-space: pre;"> error(ii)=length(find(x-z~=0));</span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper Keyword" style="color: rgb(0, 0, 255);">end</span></span>
<span class="textBox" style="white-space: pre;">semilogy(snr,error)</span>
<span class="textBox" style="white-space: pre;">hold</span>
<span class="textBox" style="white-space: pre;">snr=0:1:15;</span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper Keyword" style="color: rgb(0, 0, 255);">for </span><span class="textWrapper">ii=1:length(snr)</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> x=randint(1,100000); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Generating bits</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> y=pskmod(x,4); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Generating QPSK modulated data</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> ynoisy=awgn(y,snr(ii)); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Adding AWGN noise to data</span></span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper"> z=pskdemod(ynoisy,4); </span><span class="textWrapper Comment" style="color: rgb(34, 139, 34);">% Demodulating</span></span>
<span class="textBox" style="white-space: pre;"> error(ii)=length(find(x-z~=0));</span>
<span class="textBox" style="white-space: pre;"><span class="textWrapper Keyword" style="color: rgb(0, 0, 255);">end</span></span>
<span class="textBox" style="white-space: pre;">semilogy(snr,error)</span>
<span class="textBox" style="white-space: pre;">grid</span>
No, plot and scatter do not give you the same output graphs even though in your example they may look like the same graph.
In order to understand the difference, try reducing the number of point in x for example use x = linspace(1,20,5) and for the same value of y try plotting the two different graphs.
scatter gives you points, plot gives you a line graph by default
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