Matplotlib odd subplots

Question

I have to plot a figure with 11 subpots as you can see below. But as it is an odd number, i dont know how to deal the subplot (4,3,12) to remove it... and place the 2 last plots on the center Moreover i would like to increse the subplot size as the space is too important. The code is below.

The code is :

plt.close()

fig, axes = plt.subplots(nrows=4, ncols=3)

plt.tight_layout(pad=0.05, w_pad=0.001, h_pad=2.0)
ax1 = plt.subplot(431) # creates first axis
ax1.set_xticks([])
ax1.set_yticks([])
ax1.tick_params(labelsize=8) 
i1 = ax1.imshow(IIIm,cmap='hot',extent=(0,2000,0,2000),vmin=-0.2,vmax=-0.1)
i11 = ax1.plot((0,600),(1000,1000),'k-',linewidth=3)
cb1=plt.colorbar(i1,ax=ax1,ticks=[-0.2,-0.15,-0.1],fraction=0.046, pad=0.04,format='%.3f')
cb1.ax.tick_params(labelsize=8)
ax1.set_title("$n = -3$", y=1.05, fontsize=12)


ax2 = plt.subplot(432) # creates second axis
ax2.set_xticks([])
ax2.set_yticks([])
i2=ax2.imshow(IIm,cmap='hot',extent=(0,2000,0,2000),vmin=-0.1,vmax=0.1)
i22 = ax2.plot((0,600),(1000,1000),'k-',linewidth=3)
ax2.set_title("$n = -2$", y=1.05, fontsize=12)
ax2.set_xticklabels([])
ax2.set_yticklabels([])
cb2=plt.colorbar(i2,ax=ax2,ticks=[-0.1,0.0,0.1],fraction=0.046, pad=0.04,format='%.3f')
cb2.ax.tick_params(labelsize=8)

ax3 = plt.subplot(433) # creates first axis
ax3.set_xticks([])
ax3.set_yticks([])
i3 = ax3.imshow(Im,cmap='hot',extent=(0,2000,0,2000),vmin=-1,vmax=-0.2)
i33 = ax3.plot((0,600),(1000,1000),'k-',linewidth=3)
ax3.set_title("$n = -1$ ", y=1.05, fontsize=12)
cb3=plt.colorbar(i3,ax=ax3,ticks=[-1,-0.6,-0.2],fraction=0.046, pad=0.04,format='%.3f')
ax3.set_xticklabels([])
ax3.set_yticklabels([])
cb3.ax.tick_params(labelsize=8)
#plt.gcf().tight_layout()





#plt.tight_layout(pad=0.05, w_pad=0.001, h_pad=2.0)
ax1 = plt.subplot(434) # creates first axis
ax1.set_xticks([])
ax1.set_yticks([])
ax1.tick_params(labelsize=8) 
i1 = ax1.imshow(ZV_0_modeI,extent=(0,2000,0,2000),cmap=plt.cm.hot,origin="lower", vmin=-1, vmax=1)
i11 = ax1.plot((0,600),(1000,1000),'k-',linewidth=3)
cb1=plt.colorbar(i1,ax=ax1,ticks=[-1,0, 1],fraction=0.046, pad=0.04,format='%.2f')
cb1.ax.tick_params(labelsize=8)
ax1.set_title("$ n = 0$", y=1.05, fontsize=12)


ax2 = plt.subplot(435) # creates second axis
ax2.set_xticks([])
ax2.set_yticks([])
i2=ax2.imshow(I,cmap='hot',extent=(0,2000,0,2000), vmin=-1, vmax=1)
i22 = ax2.plot((0,600),(1000,1000),'k-',linewidth=3)
ax2.set_title("$n = 1$", y=1.05, fontsize=12)
ax2.set_xticklabels([])
ax2.set_yticklabels([])
cb2=plt.colorbar(i2,ax=ax2,fraction=0.046, pad=0.04,ticks=[-1,0,1],format='%.2f')
cb2.ax.tick_params(labelsize=8)

ax3 = plt.subplot(436) # creates first axis
ax3.set_xticks([])
ax3.set_yticks([])
i3 = ax3.imshow(II,cmap='hot',extent=(0,2000,0,2000),vmin=-1,vmax=1)
i33 = ax3.plot((0,600),(1000,1000),'k-',linewidth=3)
ax3.set_title("$n = 2$ ", y=1.05, fontsize=12)
cb3=plt.colorbar(i3,ax=ax3,fraction=0.046, pad=0.04,ticks=[-1.,0,1.],format='%.2f')
ax3.set_xticklabels([])
ax3.set_yticklabels([])
cb3.ax.tick_params(labelsize=8)
plt.gcf().tight_layout()




plt.tight_layout(pad=0.05, w_pad=0.001, h_pad=2.0)
ax1 = plt.subplot(437) # creates first axis
ax1.set_xticks([])
ax1.set_yticks([])
ax1.tick_params(labelsize=8) 
i1 = ax1.imshow(III,cmap=plt.cm.hot,origin="lower",extent=(0,2000,0,2000),vmin=-1, vmax=1)
i11 = ax1.plot((0,600),(1000,1000),'k-',linewidth=3)
cb1=plt.colorbar(i1,ax=ax1,ticks=[-1,0, 1],fraction=0.046, pad=0.04,format='%.2f')
cb1.ax.tick_params(labelsize=8)
ax1.set_title("$ n = 3$", y=1.05, fontsize=12)

ax2 = plt.subplot(438) # creates second axis
ax2.set_xticks([])
ax2.set_yticks([])
i2=ax2.imshow(IV,cmap='hot',extent=(0,2000,0,2000), vmin=-1, vmax=1)
i22 = ax2.plot((0,600),(1000,1000),'k-',linewidth=3)
ax2.set_title("$n = 4$", y=1.05, fontsize=12)
ax2.set_xticklabels([])
ax2.set_yticklabels([])
cb2=plt.colorbar(i2,ax=ax2,fraction=0.046, pad=0.04,ticks=[-1,0,1],format='%.2f')
cb2.ax.tick_params(labelsize=8)

ax3 = plt.subplot(439) # creates first axis
ax3.set_xticks([])
ax3.set_yticks([])
i3 = ax3.imshow(V,cmap='hot',extent=(0,2000,0,2000),vmin=-1,vmax=1)
i33 = ax3.plot((0,600),(1000,1000),'k-',linewidth=3)
ax3.set_title("$n = 5$ ", y=1.05, fontsize=12)
cb3=plt.colorbar(i3,ax=ax3,fraction=0.046, pad=0.04,ticks=[-1.,0,1.],format='%.2f')
ax3.set_xticklabels([])
ax3.set_yticklabels([])
cb3.ax.tick_params(labelsize=8)
plt.gcf().tight_layout()




plt.tight_layout(pad=0.05, w_pad=0.001, h_pad=2.0)
ax1 = plt.subplot(4,3,10) # creates first axis
ax1.set_xticks([])
ax1.set_yticks([])
ax1.tick_params(labelsize=8) 
i1 = ax1.imshow(VI,cmap=plt.cm.hot,origin="lower",extent=(0,2000,0,2000),vmin=-1, vmax=1)
i11 = ax1.plot((0,600),(1000,1000),'k-',linewidth=3)
cb1=plt.colorbar(i1,ax=ax1,ticks=[-1,0, 1],fraction=0.046, pad=0.04,format='%.2f')
cb1.ax.tick_params(labelsize=8)
ax1.set_title("$ n = 6$", y=1.05, fontsize=12)

ax2 = plt.subplot(4,3,11) # creates second axis
ax2.set_xticks([0])
ax2.set_yticks([])
i2=ax2.imshow(VII,cmap='hot',extent=(0,2000,0,2000), vmin=-1, vmax=1)
i22 = ax2.plot((0,600),(1000,1000),'k-',linewidth=3)
ax2.set_title("$n = 7$", y=1.05, fontsize=12)
ax2.set_xticklabels([])
ax2.set_yticklabels([])
cb2=plt.colorbar(i2,ax=ax2,fraction=0.046, pad=0.04,ticks=[-1,0,1],format='%.2f')
cb2.ax.tick_params(labelsize=8)


plt.savefig('filtre.png', dpi=250,bbox_inches='tight', pad_inches=0.1)

plt.show()

Answer 1

One way of achieving what you require is to use matplotlibs subplot2grid feature. Using this you can set the total size of the grid (4,3 in your case) and choose to only plot data in certain subplots in this grid. Below is a simplified example:

import matplotlib.pyplot as plt

x = [1,2]
y = [3,4]

ax1 = plt.subplot2grid((4, 3), (0, 0))
ax2 = plt.subplot2grid((4, 3), (0, 1))
ax3 = plt.subplot2grid((4, 3), (0, 2))
ax4 = plt.subplot2grid((4, 3), (1, 0))
ax5 = plt.subplot2grid((4, 3), (1, 1))
ax6 = plt.subplot2grid((4, 3), (1, 2))
ax7 = plt.subplot2grid((4, 3), (2, 0))
ax8 = plt.subplot2grid((4, 3), (2, 1))
ax9 = plt.subplot2grid((4, 3), (2, 2))
ax10 = plt.subplot2grid((4, 3), (3, 0))
ax11 = plt.subplot2grid((4, 3), (3, 1))

plt.subplots_adjust(wspace = 0.3, hspace = 0.3) #make the figure look better

ax1.plot(x,y)
ax2.plot(x,y)
ax3.plot(x,y)
ax4.plot(x,y)
ax5.plot(x,y)
ax6.plot(x,y)
ax7.plot(x,y)
ax8.plot(x,y)
ax9.plot(x,y)
ax10.plot(x,y)
ax11.plot(x,y)

plt.show()

This produces the figure:

Answer 2

Just don't plot anything, but set the axis off

ax = plt.subplot(4,3,12)
ax.axis('off')

You can use a loop if necessary like this

images = [rgb, depth, depth, rgb, rgb]
fig, axes = plt.subplots(rows, columns)
    for index, axis in enumerate(axes.reshape(-1)):
        if index < no_of_images:
            axis.imshow(images[index])
        axis.axis('off')