{"id":1702,"date":"2020-06-25T22:04:32","date_gmt":"2020-06-25T14:04:32","guid":{"rendered":"https:\/\/people.utm.my\/yap\/?page_id=1702"},"modified":"2020-06-25T23:25:39","modified_gmt":"2020-06-25T15:25:39","slug":"plotting-function-in-gnuplot","status":"publish","type":"page","link":"https:\/\/people.utm.my\/yap\/plotting-function-in-gnuplot\/","title":{"rendered":"Plotting Function in Gnuplot"},"content":{"rendered":"

(Back to index page<\/a>)<\/span><\/p>\n

For starters, let’s try to plot functions (without data) in Gnuplot.<\/p>\n

In a graph, you have the x and y axis.<\/span><\/p>\n

For Gnuplot, the y-axis is not called “y”… instead, you use a function to define it..<\/span><\/p>\n

e.g. y = mx + c<\/span><\/p>\n

For gnuplot, you will need to write it this way (write this in your script):\u00a0<\/strong><\/span><\/p>\n

#\u00a0 sets the number of points in the entire graph
\n<\/em>set samples 10<\/span><\/span><\/p>\n

#\u00a0 this is the function<\/em><\/span>
\nf(x) = m*x + c<\/span><\/span><\/span><\/p>\n

# define the variables that you use<\/em><\/span>
\nm = 12<\/span><\/span><\/span><\/p>\n

# define the variables that you use<\/em><\/span>
\nc = 1<\/span><\/span><\/span><\/p>\n

# this plots the f(x) function with line<\/em><\/span>
\nplot f(x) with line<\/span><\/span><\/span><\/p>\n

# replot f(x) function with points<\/em><\/span>
\nreplot f(x) with points pointtype 5<\/span><\/span><\/span><\/p>\n

 <\/p>\n

Sometimes, you will need to set the y-axis and x-axis range.\u00a0 You can use this command.<\/span><\/p>\n

# this sets the y-axis range from 0 to 10<\/em><\/span>
\nset xrange [0:5]<\/span><\/span><\/span><\/p>\n

# this sets the x-axis range from (all) to 1.5<\/em><\/span>
\nset yrange [0:60]<\/span><\/span><\/span><\/p>\n

Remember that the commands are sequential.\u00a0 So that means, it must appear before<\/strong> <\/em>the plotting command.<\/span><\/p>\n

If you change the range after<\/em> <\/strong>plotting, it will not work.<\/span><\/p>\n

If it is placed after, then you can replot existing plots using this command:<\/span><\/p>\n

# this will replot everything plotted previously.<\/span>
\nreplot<\/span><\/span><\/span><\/p>\n

\"\"<\/a><\/p>\n

\n

Let’s try a more complicated equation:<\/span><\/p>\n

Gaussian Distribution Plot<\/h2>\n

set samples 1000<\/span>
\ng(x) = a*exp((-(x-b)**2)\/(2*c**2)) + d<\/span>
\na = 2<\/span>
\nb = 3<\/span>
\nc = 1.5<\/span>
\nd = 0.2<\/span>
\nset xrange [-10:10]<\/span>
\nset yrange [0:3]<\/span>
\nplot g(x) with linespoints<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/a><\/p>\n

A multifrequency, decaying sinosoidal plot<\/h2>\n

set samples 1000<\/span>
\nh(x) = exp(-x\/t1)*A1*sin(2*pi*f1*x+phi1) + exp(-x\/t2)*A2*sin(2*pi*f2*x+phi2) – d<\/span>
\nA1 = 1<\/span>
\nA2 = 2<\/span>
\nphi1 = 0.5<\/span>
\nphi2 = 0.3<\/span>
\nt1 = 4<\/span>
\nt2 = 2<\/span>
\nf1 = 2<\/span>
\nf2 = 10<\/span>
\nd = 3<\/span>
\nset xrange [0 : 10]<\/span>
\nset yrange [-8:1]<\/span>
\nplot h(x) with line<\/span>
\n<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/a><\/span><\/p>\n

 <\/p>\n

(Back to index page<\/a>)<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

(Back to index page) For starters, let’s try to plot functions (without data) in Gnuplot. In a graph, you have the x and y axis. For Gnuplot, the y-axis is not called “y”… instead, you use a function to define it.. e.g. y = mx + c For gnuplot, you will need to write it […]<\/p>\n","protected":false},"author":14205,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"class_list":["post-1702","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/pages\/1702","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/users\/14205"}],"replies":[{"embeddable":true,"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/comments?post=1702"}],"version-history":[{"count":11,"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/pages\/1702\/revisions"}],"predecessor-version":[{"id":1736,"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/pages\/1702\/revisions\/1736"}],"wp:attachment":[{"href":"https:\/\/people.utm.my\/yap\/wp-json\/wp\/v2\/media?parent=1702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}