Matplotlib

1
PLOTTING AN INLINE GRAPH
2
Plotting an inline graph

• Inline graph can be plotted using matplotlib.It
  is a graph that contains a main graph and a
  subgraph in the same canvas.Method to plot an
  inline graphfig  plt.figure()axes1  fig.add_
  axes(0.1, 0.1, 0.9,0.9)  l,b,w,h -0 and 1
• axes2  fig.add_axes(0.55, 0.15, 0.4,0.4)  l,b,
  w,h -0 and 1
• axes1.plot(arr1, arr2)
• axes1.set_xlabel('Plotting arr1 on X Axis')
• axes1.set_ylabel('Plotting arr2 on Y Axis')
• axes1.set_title('Logarithmic graph')
• axes2.plot(arr2, arr1)
• axes2.set_xlabel('Plotting arr2 on X Axis')
• axes2.set_ylabel('Plotting arr1 on Y Axis')
• axes2.set_title('Logarithmic graph')

3

• O/P

4
Subplots() function

• This function manages axes and plots the graph
  automatically.
• It returns 2 values in the form of tuple.
• 1.figure
• 2.axes
• Egfig, axes  plt.subplots()axes.plot(arr1, arr
  2)axes.set_xlabel('Plotting arr1 on X Axis')axes
  .set_ylabel('Plotting arr2 on Y Axis')axes.set_ti
  tle('Logarithmic graph')
• O/P

5
Plotting multiple graph in 1 canvas using OOA

• Syntaxfig,axesplt.subplots(nrows,ncols)
• Egfig, axes  plt.subplots(nrows  3, ncols  2)
  axes2,1.plot(arr1,arr2)
• O/P

6
Figure size, Aspect Ratio and DPI

• Matplotlib allows the aspect ratio, DPI and
  figure size to be specified when
  the Figure object is created using
  the figsize and dpi keyword arguments.
• figsize is a tuple of the width and height of the
  figure in inches, and dpi is the dots-per-inch
  (pixel per inch).
• Higher the dpi ,clearer the image.

7

• Egfig  plt.figure(figsize  (5,4), dpi  100)a
  xes1  fig.add_axes(0.1, 0.1, 0.9,0.9)  l,b,w,h
   0 and 1axes2  fig.add_axes(0.55, 0.15, 0.4,0
  .4)  l,b,w,h 0 and 1axes1.plot(arr1, arr2)ax
  es1.set_xlabel('Plotting arr1 on X Axis')axes1.se
  t_ylabel('Plotting arr2 on Y Axis')axes1.set_titl
  e('Logarithmic graph')axes2.plot(arr2, arr1)axes
  2.set_xlabel('Plotting arr2 on X Axis')axes2.set_
  ylabel('Plotting arr1 on Y Axis')axes2.set_title(
  'Logarithmic graph')
• TO save the figurefig.savefig('log_plot.png', dp
  i 1000)

8

• O/P

9
Labels and titles

• Figure titlesA title can be added to each axis
  instance in a figure. To set the title, use
  the set_title method in the axes instance.
• Axis labelsSimilarly, with the
  methods set_xlabel and set_ylabel, we can set the
  labels of the X and Y axes.
• LegendsLegends for curves in a figure can be
  added with the legend.
• The legend function takes an optional keyword
  argument loc that can be used to specify where in
  the figure the legend is to be drawn
• Use the label"label text" keyword argument when
  plots or other objects are added to the figure.
• The following adjust the location
• ax.legend(loc0) let matplotlib
  decide the optimal location ax.legend(loc1)
  upper right corner ax.legend(loc2)
  upper left corner ax.legend(loc3)
  lower left corner ax.legend(loc4)
  lower right corner

10
Example

• fig  plt.figure()axes1  fig.add_axes(0.1, 0.1,
   0.9,0.9)  l,b,w,h -0 and 1axes2  fig.add_ax
  es(0.55, 0.15, 0.4,0.4)  l,b,w,h -0 and 1axe
  s1.plot(arr1, arr2, label  "arr2  log(arr1)")ax
  es1.set_xlabel('Plotting arr1 on X Axis')axes1.se
  t_ylabel('Plotting arr2 on Y Axis')axes1.set_titl
  e('Logarithmic graph')axes1.legend()axes2.plot(a
  rr2, arr1, label  "arr1  log(arr2)")axes2.set_x
  label('Plotting arr2 on X Axis')axes2.set_ylabel(
  'Plotting arr1 on Y Axis')axes2.set_title('Logari
  thmic graph')axes2.legend()

11
O/P
12

• Egfig, ax  plt.subplots()ax.plot(x, x2, labe
  l"y  x2")ax.plot(x, x3, label"y  x3")a
  x.legend(loc2)  upper left cornera
  x.set_xlabel('x')ax.set_ylabel('y')ax.set_title(
  'title')
• O/P