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2015-04-02 04:27:15 -0500 asked a question changing y-axis range (not just ymin , ymax)

Could anyone tell me how to change the range of y axis? I'm using semiology and ymin=0, ymax=0.3 I want to put a constant line with 0.0005. But the sage doesn't show this line on the plot. How can I change the size of interval?

this is the code and plot http://sagenb.skku.edu/home/lkijmj/14/

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2015-03-29 02:58:27 -0500 asked a question changing vertical scale of log plot

Could you please tell me how to change vertical scale in logarithmic plot?

In the following code I didn't set size of the vertical scale. So the result looks bad. How can I change the interval?

var('q1, q2, q3, q4, q5, o1, o2, o3, o4, o5, Lo1, Lo2, Lo3, Lo4, Lo5')

q1=1/20^2*exp(-20/L_s);
q2=2.4/20^2*exp(-20/L_s);
q3=4/20^2*exp(-20/L_s);
q4=5/20^2*exp(-20/L_s);
q5=15/20^2*exp(-20/L_s);

o1=plot(q1, (x, 0, 90), ymin=0, ymax=0.03, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=True, legend_label='I=1 cd', frame=True, color='yellow', title='r(distance)=20m');
o2=plot(q2, (x, 0, 90), ymin=0, ymax=0.03, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=2.4 cd', frame=True, color='red');
o3=plot(q3, (x, 0, 90), ymin=0, ymax=0.03, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=4 cd', frame=True, color='blue'); 
o4=plot(q4, (x, 0, 90), ymin=0, ymax=0.03, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=5 cd', frame=True, color='black'); 
o5=plot(q5, (x, 0, 90), ymin=0, ymax=0.03, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=15 cd', frame=True, color='green'); 
o5.set_legend_options(loc=2);

show (o1 + o2 + o3 + o4 + o5)

Lo1=plot(q1, (x, 0, 90), scale='semilogy', ymin=0, ymax=0.1, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=True, legend_label='I=1 cd', frame=True, color='yellow', title='r(distance)=20m');
Lo2=plot(q2, (x, 0, 90), ymin=0, ymax=0.1, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=2.4 cd', frame=True, color='red');
Lo3=plot(q3, (x, 0, 90), ymin=0, ymax=0.1, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=4 cd', frame=True, color='blue'); 
Lo4=plot(q4, (x, 0, 90), ymin=0, ymax=0.1, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=5 cd', frame=True, color='black'); 
Lo5=plot(q5, (x, 0, 90), ymin=0, ymax=0.1, axes_labels=['Scattering length [m]','Illuminace on camera sensor[lux]'],axes=False, legend_label='I=15 cd', frame=True, color='green'); 
Lo1.set_legend_options(loc=4);

show (Lo1 + Lo2 + Lo3 + Lo4 + Lo5)
2015-03-28 02:30:24 -0500 asked a question Error setting environment variables by sourcing

I'm a beginner of unix and struggling with problems. One of them is to run the sage in any directory by typing 'sage'. I have failed even I tried this for 4 hours. Please help me.

I'm using OS X 10.9 but I don't want to use 'alias'. As a practice I want to change PATH to make it.

I have tried

1) adding /Users/jeong/work/Sage/sage-6.4.1/local/bin to /etc/path using 'vim /etc/paths' I added it to the path. And I closed terminal. After opening it again and typing 'sage'. I got error messages

Error: You must set the SAGE_ROOT environment variable or run this script from the SAGE_ROOT or SAGE_ROOT/local/bin/ directory. Error setting environment variables by sourcing '/usr/local/bin/sage-env'; possibly contact sage-devel (see http://groups.google.com/group/sage-d...).

Even I change the '/Users/jeong/work/Sage/sage-6.4.1/local/bin' to '/Users/jeong/work/Sage/sage-6.4.1', it doesn't work.

2) making a symbolic link to /usr/local/bin command: 'ln -s /Users/jeong/work/Sage/sage-6.4.1/local/bin /usr/local/bin'

error messages :

Error: You must set the SAGE_ROOT environment variable or run this script from the SAGE_ROOT or SAGE_ROOT/local/bin/ directory. Error setting environment variables by sourcing '/usr/local/bin/sage-env'; possibly contact sage-devel (see http://groups.google.com/group/sage-d...).

3) making .bash_profile or changing .profile in the home directory

don't work.

Please help me

2015-03-26 23:00:24 -0500 commented answer Unable to simplify to float approximation

Thank you for the answer. So does it mean this is responsible of Maxima or Sage? Not my code?

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2015-03-26 22:09:38 -0500 marked best answer Dropping higher order terms in polynomials.

Dear all,

could you please let me know how to write a code? I just get started with the SAGE and met a trouble. When I put the followings

f=e^x; f

then the output is a polynomial function with 16th order. But I wanted to drop the higher order terms and just take 3 tems. However I have no idea how to do it. It seems the truncate() or power_series(ZZ) don't work for the exponential function. Could anyone give me the solution?

thank you.

2015-03-26 07:51:36 -0500 asked a question comparison between Root, mathematica and sage?

After getting started with Sage, I have experienced lots of anger and stress. Because I'm not aware of the codes and errors. Especially I don't understand the error code. It is quite different form GCC or something. Even I read the error report, I can't figure out exactly what the problem is. So I'm thinking of moving to mathematica or something. But I wonder if it worth is to learn the sage more. Even I hate the maxima in integrations. Could you please tell me what benefit the sage has? Or if I should use ROOT, then would it be better just move to the ROOT? In principle, the ROOT is data analysis package. But people say that they can replace mathematica as the SW. If it is possible. I would move.

2015-03-26 07:36:10 -0500 asked a question Unable to simplify to float approximation

I have been struggling with an integration. When I tried symbolic integral, the sage didn't give any answer and stopped working. And then it gave errors for various numerical integral commands. Could you please let me know what the problem is and how to fix it is the code I used. I'm sorry for this long code. but It was necessary.

var('T1, T2, T3, T4, T5, T6, T7, T8, r, r_0, r_2, r_a, r_s,theta_a, phi_a, theta_c, theta, phi, A');

r_a=2;

theta_a=pi/2;

phi_a=0;

r_s=vector([r, theta, phi]);

r_0=vector([r_a, theta_a, phi_a]);

T1=vector ([sin(theta)*cos(phi), sin(theta)*sin(phi), cos(theta)]);

T2=vector ([cos(theta)*cos(phi), cos(theta)*sin(phi), -sin(theta)]);

T3=vector ([-sin(phi), cos(phi), 0]);

T5=vector ([sin(theta_a)*cos(phi_a), sin(theta_a)*sin(phi_a), cos(theta_a)]);

T6=vector ([cos(theta_a)*cos(phi_a), cos(theta_a)*sin(phi_a), -sin(theta_a)]);

T7=vector ([-sin(phi_a), cos(phi_a), 0]);

var('L_s, SA_0, SA_1, SA_2, theta_h, I_0, I, rho, I_1, Phi_0, Phi_1, Phi_2, E_v') ;

L_s=20;

I_0=2.4; 

theta_h= 2*pi/45; 

Phi_0=I_0*SA_0; 

Phi_0;

T4=matrix ([T1, T2, T3]);

T8=matrix ([T5, T6, T7]);

(r_s*T4)*(r_0*T8);

A=((r_s*T4)*(r_0*T8));

theta_c=arccos(A/(r*r_a));

r_2=sqrt(r^2+r_a^2-2*r*r_a*cos(theta_c)); 

Phi_0 ;

Phi_0*(1-exp(-r/L_s));

f=diff(Phi_0*(1-exp(-r/L_s)), r); f

plot (f, xmin=0, xmax=20, ymin=0, ymax=0.01) ;

rho=1/(SA_0*r^2)*f; rho; SA_0; f;

y=rho/(r_2)^2*r^2*sin(theta)^2;

numerical_integral(lambda phi: numerical_integral(lambda theta: numerical_integral(lambda r: y, 0,5)[0], 0, pi)[1], 0, pi)
2015-02-13 01:34:10 -0500 asked a question How can I print equations just like latex?

Now I'm testing several equations and solutions with Sage. After testing the solutions, I'd present it to the group members. But I met a problem to print the equations.

For example, when I write the code.

sage: z(x)=6/(5*pi*50*(x^2+25))*exp((-x+sqrt(x^2+25))/50)
sage: view (z)

Then the sage doesn't show the equation that is exactly same with the code, but it just shows simplified form. Could anyone let me know how to show the original equation?

And it would be also appreciated, if you tell me how to modify the simplifying mechanism. I'd love to write equations that don't contain any large denominators with many exponential terms.

thank you.

2015-02-11 08:47:34 -0500 commented answer How long does it take to compile the SAGE from its source?

Oh, Thank you again for the comment. I'd do it when I compile other packages.

2015-02-11 04:07:54 -0500 commented answer How long does it take to compile the SAGE from its source?

I appreciate for the explanation. Actually I typed the "make" more than 12 hours ago and went to bed. I thought it stopped due to battery-saving sleep mode. But now I see it took about 15hours. I can use SAGE now. But it's quite surprising.

I'm afraid that I put my macbook on soft cover...I do this always to avoid scratches. But I checked often the temperature of CPU and MB using widget to see RAM usage and the temperature was always below 55 degree(C). There might be no problem.

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2015-02-11 03:52:50 -0500 commented answer what is "....:"?

Thank you so much! Now I see what happened.

2015-02-11 00:03:57 -0500 asked a question what is "....:"?

I have just installed Sage and tested it with some equations. But I found a problem that the left side of the command line changes from "sage: " to "....: ". It was the case when I typed the following code.

f(x)=2.4/x^2*(1-e^(-x/50))

Could anyone let me know what "....:" means? And how to recover the normal command line in order to use Sage again? With "....: " it seems that Sage never work.

Thank you.

2015-02-10 22:10:07 -0500 edited question How long does it take to compile the SAGE from its source?

About 5 hours ago I had typed all commands for compiling the Sage from its source. After typing "make" I have been waiting until the process is completed. But still it doesn't stop and I'm afraid that there might be a problem. Could you please tell me how long time does it take to compile the sage from its source? Is it usually more than 6 hours? I'm using Macbook Pro 2013late. So cpu, RAM are not so bad. I can't understand why the sage doesn't finish the installation.