2019-08-07 08:50:12 -0600 received badge ● Notable Question (source) 2019-01-03 09:08:48 -0600 received badge ● Famous Question (source) 2017-11-15 00:25:13 -0600 received badge ● Notable Question (source) 2017-10-23 18:06:19 -0600 received badge ● Popular Question (source) 2017-03-10 02:21:49 -0600 received badge ● Popular Question (source) 2016-01-18 13:55:38 -0600 received badge ● Notable Question (source) 2015-03-14 20:02:20 -0600 received badge ● Popular Question (source) 2014-10-28 09:23:42 -0600 received badge ● Taxonomist 2014-06-29 14:34:48 -0600 received badge ● Popular Question (source) 2014-06-29 14:34:48 -0600 received badge ● Notable Question (source) 2013-05-13 12:36:49 -0600 answered a question Problem with conjugate_transpose of a symbolic matrix Sorry, Ta was a typo and should not be there. I used dAbar = dAbar.dense_matrix() and all is good. Thanks so much tmonteil. nonlinear 2013-05-12 15:56:25 -0600 answered a question Problem with conjugate_transpose of a symbolic matrix var('t,x3') p1= -3+2.5*tanh(2.*t)+(3.19*sech(x3)-2.69)*I p2= -3+2.5*tanh(2.*t)-(3.19*sech(x3)-2.69)*I p3=-4 diagAbar= diagonal_matrix(Ta.[p1,p2,p3]) dAbar=diagAbar.subs(t=0);dAbar  Playing around with dAbar I found that: TdiagAbar=dAbar.conjugate()  works, but TdiagAbar=dAbar.transpose()  and TdiagAbar=dAbar.conjugate()+dAbar  do not work. Sorry, I didn't follow much of what link said. I do a lot of symbolic math with symbolic variables such as with t and x3 above. I know MATLAB well and Mathematica somewhat. I would prefer to support Sage. Thanks for your help. nonlinear 2013-05-11 16:46:41 -0600 asked a question Problem with conjugate_transpose of a symbolic matrix dAbar=diagAbar.subs(t=0);dAbar [ 3.18953143618644*I*sech(x3) - 3.00000000000000 - 2.68953143618644*I 0 0] [ 0 -3.18953143618644*I*sech(x3) - 3.00000000000000 + 2.68953143618644*I 0] [ 0 0 -4] TdiagAbar=dAbar.conjugate_transpose() + dAbar Traceback (click to the left of this block for traceback) ... AttributeError: 'sage.rings.complex_interval.ComplexIntervalFieldElement' object has no attribute 'sech'  I hope their is an easy answer. Thanks, nonlinear 2013-05-06 19:18:24 -0600 asked a question adjoint() does not work with trig functions. adjoint() works for symbolic matrices except for those that have trig functions such as tan, sec, or tanh in their entries. Is there an easy way around this or do I need to create my own ajdoint() function? Thanks much. nonlinear 2013-05-06 19:08:09 -0600 answered a question Conversion of Differential Forms to a manipulable symbolic expression Thanks much. However, I have found a better way as follows: sage: t, x3, dx3 = var('t x3 dx3') sage: a = matrix([[x3+t,2,x3],[t^2,5,x3],[t,x3,x3^2]]) sage: b = derivative(a,t); b [ 1 0 0] [2*t 0 0] [ 1 0 0] sage: c = derivative(a,x3); c [ 1 0 1] [ 0 0 1] [ 0 1 2*x3] sage: d = b+dx3*c; d [ dx3 + 1 0 dx3] [ 2*t 0 dx3] [ 1 dx3 2*dx3*x3]  2013-05-04 16:04:16 -0600 asked a question Conversion of Differential Forms to a manipulable symbolic expression [Sage 5.4.1] Hi, I got the following code that does total differentiation off a Sage blog: sage: x, y, z = var('x, y, z') sage: U = CoordinatePatch((x, y, z)) sage: F = DifferentialForms(U) sage: f = F(x^2 + y + sin(z)); f (x^2 + y + sin(z)) sage: g = f.diff(); g cos(z)*dz + 2*x*dx + dy  How do I convert g to a symbolic form where dx, dy, and dz are also symbolic variables? I need to assign values to all variables via a for loop. Also, is it possible for g to be a 3x3 matrix? Thanks much, mahlon 2012-11-30 17:39:31 -0600 commented answer creating a matrix from blocks Thanks much, but I still get a syntax error. I have double checked the matrices A,B,C,D, and E by using print and dimensions are correct. The matrices do contain symbolic variables that have been defined using var. Any suggestions? Thanks. 2012-11-30 13:16:53 -0600 answered a question creating a matrix from blocks Thanks much, but I still get a syntax error. I have double checked the matrices A,B,C,D, and E by using print and dimensions are correct. The matrices do contain symbolic variables that have been defined using var. Any suggestions? Thanks. 2012-11-29 18:27:49 -0600 received badge ● Student (source) 2012-11-29 12:30:58 -0600 asked a question creating a matrix from blocks I am new to SAGE. I need to create a matrix by using matrices of different sizes. For example: Abar= [(A + B), C] [ D , E]  where A and B are 2x2's, C is a 2x1, D is a 1x2, and E is a 1x1. I do not need Abar to be a partitioned matrix. Thanks much.