Student Support Forum: '3D Point Plots' topicStudent Support Forum > General > "3D Point Plots"

 < Previous Comment Help | Reply To Comment | Reply To Topic
 Author Comment/Response Forum Moderator email me 09/30/99 06:32am >I hope someonw can help me.>I am trying to plot points in 3D space of varying sizes. (These are specific points and sizes that I provide). >I have put the data in an n x 4 matix (we'll call it 'sample' here) of the form: > >sample = >{{1, 1, 1, 1}, >{1, 2, 3, 3}, >{3, 4, 5, 2}, >{1, 2, 5, 3}, >. . . . (and so on for thousands of lines) > >I would like to extract the first 3 terms of each line as the x,y,z coordinates of the points and last term of each line as the size (using the AbsolutePointSize command). >What I came up with is the following command'' > >Show [ Graphics3D [{ AbsolutePointSize [ Part [ sample, 4]], Point [ Part [ sample, { 1, 2, 3 }]]}]] > >I know something is wrong with the Part statements cuz it's extract the whole line, instead of the parts of each line. Also, I don't know that if I do get the Part commands right if it'll work. Should I be using the ScatterPlot3D command instead? >(Sorry if this sounds silly or easy, but this is the FIRST time I have ever used Mathematica) >Thanks, >Tony >UCLA >Dept. of OBEE ========= You are not far off. Your code does not quite take apart the ''points'' in your data: In[7]:=sample = {{1, 1, 1, 1}, {1, 2, 3, 3}, {3, 4, 5, 2}, {1, 2, 5, 3}} Out[7]= {{1,1,1,1},{1,2,3,3},{3,4,5,2},{1,2,5,3}} In[8]:= { AbsolutePointSize [ Part [ sample, 4]], Point [ Part [ sample, { 1, 2, 3 }]]} Out[8]={AbsolutePointSize[{1,2,5,3}],Point[{{1,1,1,1},{1,2,3,3},{3,4,5,2}}]} However, if you ''go down a level'', you can get at the coordinates. Here is an example using the firs element of sample: In[9]:={ AbsolutePointSize [ Part [ sample,1, 4]], Point [ Part [ sample,1, { 1, 2, 3 }]]} Out[9]= {AbsolutePointSize[1],Point[{1,1,1}]} You could use table to build such an expression for each of the elements of sample: In[10]:= samplePoints = Table[{ AbsolutePointSize [ Part [ sample,i, 4]], Point [ Part [ sample,i, { 1, 2, 3 }]]}, {i, 1, Length[sample]}] Out[10]= {{AbsolutePointSize[1],Point[{1,1,1}]},{AbsolutePointSize[3],Point[{1,2,3}]},{ AbsolutePointSize[2],Point[{3,4,5}]},{AbsolutePointSize[3], Point[{1,2,5}]}} Then the points can be displayed: In[11]:= Show[Graphics3D[samplePoints]] Tom Zeller Forum Moderator URL: ,

 Subject (listing for '3D Point Plots') Author Date Posted 3D Point Plots Tony Friscia 09/30/99 06:12am Re: 3D Point Plots Forum Modera... 09/30/99 06:32am
 < Previous Comment Help | Reply To Comment | Reply To Topic