jmarcellopereira's profile - activity

I got a way to solve the differential equation. If wrong please correct;)

To solve this differential equation we must first make a variable substitution to reduce the differential equation for a first order and thus create a system of ODEs. variable change:

w1 = y w2 = y w3 = y '

Thus, deriving the above variables, we have a system of equations of the form:

w1 '= w2 w2 '= f (x, w1, w2) = 4 * w2 + x

desolve_system_rk4([w2, 4*w2 + x ],[w1 , w2], ics = [0,1,0],ivar = x, step = 0.1, end_points = 2)

I tryed

 # w = y''
 # z = y'

var('x, w, z')

desolve_system_rk4( [w , 4*z + x] , [w,z] , ics = [0,1,0], ivar = x, end_points = 10, step = 0.1)

But does no work correty :(

How to solve ODE y''+y''-4y'+x = 0 using rk4?

How to install seaborn in sagemath cloud?

I got this: in SageMath folder ( uncompressed )

 $ Sudo ./sage

wait compile and then delete the " .sage " folder in /home/user.

$ ./sage

hi, willmwade how to discovery the function of item [0]?

let try:

open terminal virtual machine and type:

   $ ifconfig

copy the ip

after, type:

    $ sage

    sage: notebook(interface=' ')

in firefox, by host machine, use: ip_virtual_machine:8080

How to numerical double integral?

when I use the worksheet to evaluate sagemath sage code, the result is better presented on the screen (here will not be shown). In Maxima the code result leaves unformatted.

I really want to see the graphics out of sagemath, in another window (ex: gnuplot.plot3d (f = 'cos (x) + sin (y) * 2', xmin = -1, xmax = 1, ymin = -1, ymax = 1, -1 = zmin, zmax = 1, title = None, samples = 25 = 20 isosamples, xlabel = x, ylabel = 'y', interact = True)). Is okay only the first visualization, then does not work. I could not see 2d.

I really want to see the graphics out of sagemath, in another window (ex: gnuplot.plot3d (f = 'cos (x) + sin (y) * 2', xmin = -1, xmax = 1, ymin = -1, ymax = 1, -1 = zmin, zmax = 1, title = None, samples = 25 = 20 isosamples, xlabel = x, ylabel = 'y', interact = True)). Is okay only the first visualization, then does not work. I could not see 2d.

Hi

I solved the problem I created the file function fiboR_SG.py below

def fiboR_SG(n):

if n < 2:

    return n

else:

    return fiboR_SG(n-1) + fiboR_SG(n-2)

upload fiboR_SG.py using "DATA" in Worksheet menu. In the "You may download fiboR_SG.py or create a link to this file in worksheet" select your worksheet. Back worksheet and use: import fiboR_SG ("no .py")

fiboR_SG. fiboR_SG(10)

55

OK :)

Hi

I solved the problem I created the file function fiboR_SG.py below

def fiboR_SG(n) :
   if n < 2:
      return n
   else:
      return fiboR_SG(n-1) + fiboR_SG(n-2)

upload fiboR_SG.py using "DATA" in Worksheet menu. In the "You may download fiboR_SG.py or create a link to this file in worksheet" select your worksheet. Back worksheet and use: import fiboR_SG ("no .py")

fiboR_SG. fiboR_SG(10)
55

OK :)

I tryed, but: make: * No rule to make target 'all-toolchain'. Stop. how to solve?

Hello tmolteil

my files are on the local machine and the sagemath runs on the virtual machine. I tried that way, but only import virtual machine files, not the host machine.

i want to import a file function called "function.py" to my Worksheet. How to do?

how to user a external program to plot graphic? ex: gnuplot, xmaxima, mgnuplot....

I use Maxima with sagemath and do not know why the results are not rendered

sage: f(x):=x^2
f(x):=x^2
sage: integrate(f(x),x)
x^3/3

how to add julia in sagemath notebook?

marked ;)

get the model coefficients, but I can not use them to plot the graph. How to solve?

see the code:

dados = [(0, -0.183440428023042),
 (0.200000000000000, -0.131101157495126),
 (0.400000000000000, 0.0268875670852843),
 (0.800000000000000, 0.110532679260319),
 (1.00000000000000, 0.253944632998395),
 (1.20000000000000, 0.257190123748649),
 (1.40000000000000, 0.531888837111346),
 (1.60000000000000, 0.579048247883555),
 (2.00000000000000, 0.935180993484717),
 (2.20000000000000, 0.916600344376623),
 (2.60000000000000, 1.13328608090532),
 (2.80000000000000, 1.26893326843583),
 (3.00000000000000, 1.10202945535186),
 (3.40000000000000, 1.13391615491257)]

point(dados,color = "red",size=20,legend_label="pontos coletados")

modelo(x) = a*x+b;modelo

a,b = find_fit(dados, modelo);a;b

modelo(x) = a*x+b

point(dados,color = "red",size=20,legend_label="pontos coletados") + plot(modelo(x),(x,0,3))
Traceback (click to the left of this block for traceback)
...
ValueError: Variable 'x' not found