Further Examples: Total

Here is a list of numbers.

In[1]:=

This gives the sum.

In[2]:=

Out[2]=

This does the same thing.

In[3]:=

Out[3]=

The head need not be Plus.

In[4]:=

Out[4]=

Here is a nested list.

In[5]:=

This gives the sum of the elements of .

In[6]:=

Out[6]=

Here is a list of million pseudorandom real numbers between and .

In[7]:=

Total is much faster than Plus in summing the elements of ..

In[8]:=

Out[8]=

In[9]:=

Out[9]=

Total also gives the sum of symbolic lists.

In[10]:=

Out[10]=

In[11]:=

Out[11]=

In[12]:=

Out[12]=

In[13]:=

Out[13]=

Here is an expression.

In[14]:=

Here Total sums all expressions with head equal to .

In[15]:=

Out[15]=

In[16]:=

Out[16]=

Here is a list of two matrices.

In[17]:=

Out[17]=

This adds the matrices.

In[18]:=

Out[18]//MatrixForm=

This adds the rows of the sum of the matrices.

In[19]:=

Out[19]//MatrixForm=

This adds all the elements of the matrices.

In[20]:=

Out[20]=

This gives the precision of a machine number on any given computer, whether 16-bit, 32-bit, or 64-bit.

In[21]:=

Out[21]=

Here is a list of numbers.

In[22]:=

Out[22]=

Neither Plus nor Total register the sum of the small numbers in .

In[23]:=

Out[23]//FullForm=

In[24]:=

Out[24]//FullForm=

Using the option Total gives a result closer to the true sum.

In[25]:=

Out[25]//FullForm=

In[26]:=

Out[26]//FullForm=