Use of erf(x); read text file; command to display available functions

To find the size of a matrix which is a list of lists, you can use length(),  for one dimension, and
length(part(%,1)), for the other.

Does this demand a function all by itself? You can obviously write one.

As for plotting matrices, i think that you can take the first row of a matrix and treat it as a list  by using part,
and if you want a column, try transposing the matrix.

In these cases as in many others there is a balance between having a separate command to do each imaginable thing, or in having fewer but more versatile commands that require some arrangement (programming!) by the user.

People have different balance points.  And obviously documentation makes a difference.
RJF
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Is there a function that returns the size of a matrix: for example, if
M is a matrix of dimension nxm, the function size(M) would return the
list [n,m]? Such a function does not appear in the reference manual
matrix chapter.
 
Apparently, plot2d will not plot a matrix that is 1xn or mx1; it only
plots lists (or functions). So, to plot a matrix, for example
columnwise, it is necessary to write a separate function to pick off
the columns, convert them to lists, and plot one-by-one. Am I missing
something? It would be good to make plotting work with any data type in
Maxima. That avoids writing special functions for conversions and makes
use of the tool more uniform.
 
Regards.
 


________________________________

	From: Bartlett, Charles S. 
	Sent: Tuesday, August 14, 2007 10:28 AM
	To: 'maxima at math.utexas.edu'
	Subject: RE: Use of erf(x); read text file; command to display
available functions
	
	
	Apparently, the package numericalio provides facility for my
2nd question.
	 
	Thanks for the answers to my first. erf(5.0) returns a
numerical result.
	 
	I am still interested in receiving an answer to my 3rd
question. How do you have Maxima list all available functions - i.e.
those that are built-in, those that are loaded from a package, and
those I define. The "functions" command handles the latter only,
apparently.
	 
	Thanks.
	 
________________________________

	From: Bartlett, Charles S. 
	Sent: Monday, August 13, 2007 3:08 PM
	To: 'maxima at math.utexas.edu'
	Subject: Use of erf(x); read text file; command to display
available functions
	
	

		Why doesn't erf(5) produce a numerical result, whereas
sin(.3) or gamma(.2) do?
		 
		I am using Maxima 5.12.0.
		 
		It appears that my version is not finding a definition
for erf.
		 
		--------------------
		 
		Can Maxima read a text file containing a column of
numbers?
		 
		 
		--------------------
		 
		Is there a function to display available functions -
not just those defined by a user?
		 
		 
		 
		 
		Thanks.
		
		

			 

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