Re: Could we build matrix with codition instruction?
- To: mathgroup at smc.vnet.net
- Subject: [mg23347] Re: [mg23314] Could we build matrix with codition instruction?
- From: Matt.Johnson at autolivasp.com
- Date: Thu, 4 May 2000 02:59:15 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
This may not be the most eloquent way, but
In[53]:=
mat = Array[f, {4, 4}]
Out[53]=
{{f[1, 1], f[1, 2], f[1, 3], f[1, 4]}, {f[2, 1], f[2, 2], f[2, 3],
f[2, 4]}, {f[3, 1], f[3, 2], f[3, 3], f[3, 4]}, {f[4, 1], f[4, 2],
f[4, 3], f[4, 4]}}
In[57]:=
g[i_, j_] := If[(j - i) >= 0, mat[[i, j]] = 1, mat[[i, j]] = 0]
In[62]:=
Table[g[i, j], {i, 4}, {j, 4}]
Out[62]=
{{1, 1, 1, 1}, {0, 1, 1, 1}, {0, 0, 1, 1}, {0, 0, 0, 1}}
In[61]:=
mat
Out[61]=
{{1, 1, 1, 1}, {0, 1, 1, 1}, {0, 0, 1, 1}, {0, 0, 0, 1}}
-matt
Coase Yang <cnc at ms6.hinet.net> on 05/01/2000 04:00:15 PM
Subject: [mg23347] [mg23314] Could we build matrix with codition instruction?
Dear All:
I want to construct an 4*4 upper triangular matrix with
conditional instruction, a[i,j]:
if j-i>=0, then a[[i,j]]=1
if j-i<0, then a[[i,j]]=0
Could anyone tell me how I could build this matrix with
list or Table form by conditional instruction inside?
Thank you very much.
Coase Yang