Further Examples: PadRight

Padding a list

This makes a list of length by padding to the right with x's.

In[1]:=

Out[1]=

Using gives padding on the left.

In[2]:=

Out[2]=

Using an empty list, you can see how a cyclic padding ends on the first element of the padding.

In[3]:=

Out[3]=

Now the nonempty list is superimposed on the padding.

In[4]:=

Out[4]=

Here the list is padded on the left by elements.

In[5]:=

Out[5]=

And here the first elements of the list are dropped.

In[6]:=

Out[6]=

This treats the list as cyclic.

In[7]:=

Out[7]=

This has the same effect.

In[8]:=

Out[8]=

Padding a matrix

This pads a matrix to give rows and columns.

In[9]:=

Out[9]//MatrixForm=

This does the same thing, but uses a block to provide the padding.

In[10]:=

Out[10]//MatrixForm=

This shifts the matrix down row and to the right columns.

In[11]:=

Out[11]//MatrixForm=

Padding graphics

Here is a nested list.

In[12]:=

Out[12]//MatrixForm=

This represents the list using Raster. (Raster starts from the lower-left corner so the picture seems upside-down.)

In[13]:=

Here the list is padded.

In[14]:=

Out[14]//MatrixForm=

In[15]:=

Here are two different paddings.

In[16]:=

Out[16]//MatrixForm=

In[17]:=

In[18]:=

Out[18]//MatrixForm=

In[19]:=

Making a Block Diagonal Matrix

This defines the function BlockDiagonalMatrix which creates a block diagonal matrix from a list of matrices.

In[20]:=

Here are four matrices.

In[21]:=

Out[21]//MatrixForm=

In[22]:=

Out[22]//MatrixForm=

In[23]:=

Out[23]//MatrixForm=

In[24]:=

Out[24]//MatrixForm=

Here is the block diagonal matrix constructed from the four matrices.

In[25]:=

Out[25]//MatrixForm=

In[26]:=