Senin, Juni 29, 2015
Kamis, Juni 25, 2015
Minggu, Juni 21, 2015
cara membuat grafik dengan scrib pada matlab
Buka aplikasi MATLAB
kemuduan lakukan langkah-langkah berikut:
1. pilih dan klik file.
2. pilih New >>> lalu pilih M-file.
3.Ketikan datan sebagai berikut:
% cara membuat grafik
dengan scrib
x=[1:5]
y=x.^2
plot(x,y)
4. Tekan F5, dan simpan file dengan nama grafikdenganscrib
5. dan diperoleh hasil sbb:
SELAMAT MENCOBA!!!
Selasa, Juni 16, 2015
function pada matlab
setelah m-file terbuka ketikkan sebagai berikut:
function ll=luaslingkaran(r);
ll=pi*r.^2; end
setelah memasukkan fungsi di atas, simpan data dengan nama luaslingkaran.m.(tekan F5 untuk meng eksekusi) setelah tersimpan maka buka command window dan ketikkan sbb:
ll=luaslingkaran(7)
dan akan diperleh hasil:
ll=154 silahkan mencoba!
function ll=luaslingkaran(r);
ll=pi*r.^2; end
setelah memasukkan fungsi di atas, simpan data dengan nama luaslingkaran.m.(tekan F5 untuk meng eksekusi) setelah tersimpan maka buka command window dan ketikkan sbb:
ll=luaslingkaran(7)
dan akan diperleh hasil:
ll=154 silahkan mencoba!
Selasa, Juni 02, 2015
polyval Matlab
Contoh polyval…
Examples This example involves fitting the error function, erf(x), by a polynomial in x.
This is a risky project because erf(x) is a bounded function, while polynomials are unbounded, so the fit might not be very good. First generate a vector of x points, equally spaced in the interval ; then evaluate erf(x) at those points.
x = (0: 0.1: 2.5)'; y = erf(x);
The coefficients in the approximating polynomial of degree 6 are
p = polyfit(x,y,6) p = 0.0084 -0.0983 0.4217 -0.7435 0.1471 1.1064 0.0004
There are seven coefficients and the polynomial is To see how good the fit is, evaluate the polynomial at the data points with
f = polyval(p,x);
A table showing the data, fit, and error is table = [x y f y-f] table = 0 0 0.0004 -0.0004 0.1000 0.1125 0.1119 0.0006 0.2000 0.2227 0.2223 0.0004 0.3000 0.3286 0.3287 -0.0001 0.4000 0.4284 0.4288 -0.0004 ... 2.1000 0.9970 0.9969 0.0001 2.2000 0.9981 0.9982 -0.0001 2.3000 0.9989 0.9991 -0.0003 2.4000 0.9993 0.9995 -0.0002 2.5000 0.9996 0.9994 0.0002
So, on this interval, the fit is good to between three and four digits. Beyond this interval the graph shows that the polynomial behavior takes over and the approximation quickly deteriorates.
x = (0: 0.1: 5)'; y = erf(x); f = polyval(p,x); plot(x,y,'o',x,f,'-') axis([0 5 0 2])
Algorithm The polyfit M-file forms the Vandermonde matrix, , whose elements are powers of . It then uses the backslash operator, \, to solve the least squares problem You can modify the M-file to use other functions of as the basis functions.
Examples This example involves fitting the error function, erf(x), by a polynomial in x.
This is a risky project because erf(x) is a bounded function, while polynomials are unbounded, so the fit might not be very good. First generate a vector of x points, equally spaced in the interval ; then evaluate erf(x) at those points.
x = (0: 0.1: 2.5)'; y = erf(x);
The coefficients in the approximating polynomial of degree 6 are
p = polyfit(x,y,6) p = 0.0084 -0.0983 0.4217 -0.7435 0.1471 1.1064 0.0004
There are seven coefficients and the polynomial is To see how good the fit is, evaluate the polynomial at the data points with
f = polyval(p,x);
A table showing the data, fit, and error is table = [x y f y-f] table = 0 0 0.0004 -0.0004 0.1000 0.1125 0.1119 0.0006 0.2000 0.2227 0.2223 0.0004 0.3000 0.3286 0.3287 -0.0001 0.4000 0.4284 0.4288 -0.0004 ... 2.1000 0.9970 0.9969 0.0001 2.2000 0.9981 0.9982 -0.0001 2.3000 0.9989 0.9991 -0.0003 2.4000 0.9993 0.9995 -0.0002 2.5000 0.9996 0.9994 0.0002
So, on this interval, the fit is good to between three and four digits. Beyond this interval the graph shows that the polynomial behavior takes over and the approximation quickly deteriorates.
x = (0: 0.1: 5)'; y = erf(x); f = polyval(p,x); plot(x,y,'o',x,f,'-') axis([0 5 0 2])
Algorithm The polyfit M-file forms the Vandermonde matrix, , whose elements are powers of . It then uses the backslash operator, \, to solve the least squares problem You can modify the M-file to use other functions of as the basis functions.
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