Welch's t-test: Difference between revisions
Content added Content deleted
| Line 195: | Line 195: | ||
=={{header|Fortran}}== |
=={{header|Fortran}}== |
||
=== Using IMSL === |
|||
Using IMSL '''TDF''' function. With Absoft Pro Fortran, compile with <code>af90 %FFLAGS% %LINK_FNL% pvalue.f90</code>. |
Using IMSL '''TDF''' function. With Absoft Pro Fortran, compile with <code>af90 %FFLAGS% %LINK_FNL% pvalue.f90</code>. |
||
Alternatively, the program shows the p-value computed using the IMSL '''BETAI''' function. |
Alternatively, the program shows the p-value computed using the IMSL '''BETAI''' function. |
||
| Line 229: | Line 229: | ||
<pre> -9.55949772193266 2.00085234885628 1.075156114978449E-002 |
<pre> -9.55949772193266 2.00085234885628 1.075156114978449E-002 |
||
1.075156114978449E-002</pre> |
1.075156114978449E-002</pre> |
||
=== Using SLATEC === |
|||
With Absoft Pro Fortran, compile with <code>af90 pvalue_slatec.f90 %SLATEC_LINK%</code>. |
|||
<lang fortran>subroutine welch_ttest(n1, x1, n2, x2, t, df, p) |
|||
implicit none |
|||
integer :: n1, n2 |
|||
double precision :: x1(n1), x2(n2) |
|||
double precision :: m1, m2, v1, v2, t, df, p |
|||
double precision :: dbetai |
|||
m1 = sum(x1) / n1 |
|||
m2 = sum(x2) / n2 |
|||
v1 = sum((x1 - m1)**2) / (n1 - 1) |
|||
v2 = sum((x2 - m2)**2) / (n2 - 1) |
|||
t = (m1 - m2) / sqrt(v1 / n1 + v2 / n2) |
|||
df = (v1 / n1 + v2 / n2)**2 / & |
|||
(v1**2 / (n1**2 * (n1 - 1)) + v2**2 / (n2**2 * (n2 - 1))) |
|||
p = dbetai(df / (t**2 + df), 0.5d0 * df, 0.5d0) |
|||
end subroutine |
|||
program pvalue |
|||
implicit none |
|||
double precision :: x(4) = [3d0, 4d0, 1d0, 2.1d0] |
|||
double precision :: y(3) = [490.2d0, 340.0d0, 433.9d0] |
|||
double precision :: t, df, p |
|||
call welch_ttest(4, x, 3, y, t, df, p) |
|||
print *, t, df, p |
|||
end program</lang> |
|||
'''Output''' |
|||
<pre> -9.55949772193266 2.00085234885628 1.075156114978449E-002</pre> |
|||
=={{header|Go}}== |
=={{header|Go}}== |
||