I'm writing VB Code and I see a question below
There are three positive integers A, B, C
If A is greater than B, C is equal to A+B
If A is less than or equal to B, then C is equal to A-B.
Please use IF...Then and Select/Switch Case to write a program, both of which are used in this program, and additional variables can be added by yourself.
I would like to ask how to write this question, as far as I know, the answer just need only IF Then or Select Case can be realized?
Dim A As Double = 3
Dim B As Double = 2
Dim C As Double = 1
Dim D As Double = 0
D = A - B
Select Case D
Case D > 0
C = A + B
Case D < 0
C = A - B
End Select
If D > 0 Then
C = A + B
ElseIf D < 0 Then
C = A - B
End If
In the real world you wouldn't need to use both an If/Then statement and a Select/Case statement. Since this appears to be homework, I believe the exercise is to see if you can use both conditional check.
I would setup two functions that accept two arguments (a and b) that return the value of c. In your first function use an If/Then and in your second function use a Select/Case.
E.g.
Private Function IfThenOption(a As Integer, b As Integer) As Integer
Dim c As Integer
If (a > b) Then
c = a + b
ElseIf (a < b) Then
c = a - b
Else
c = a
End If
Return c
End Function
Private Function SelectCaseOption(a As Integer, b As Integer) As Integer
Dim c As Integer
Select Case True
Case a > b
c = a + b
Case a < b
c = a - b
Case Else
c = a
End Select
Return c
End Function
Example: https://dotnetfiddle.net/kwcyWc
Related
I'm trying to create a code that uses the false position method to find the roots of an equation. The equation is as follows:
y = x^(1.5sin(x)) * e^(-x/7) + e^(x/10) - 4
I used a calculator to find the roots, and they are 6.9025, 8.8719, and 12.8079.
My VBA code is as follows:
Option Explicit
Function Func(x)
Func = (x ^ (1.5 * Sin(x))) * Exp(-x / 7) + Exp(x / 10) - 4
End Function
Function FalsePos(Guess1, Guess2)
Dim a, b, c As Single
Dim i As Integer
a = Guess1
b = Guess2
For i = 0 To 1000
c = a - Func(a) * (b - a) / (Func(b) - Func(a))
If (Func(c) < 0.00001) Then
i = 1001
Else
If Func(a) * Func(c) < 0 Then
b = c
Else
a = c
End If
End If
Next
FalsePos = c
End Function
My problem is that when I call the function and use for example 4 and 8 as my two guesses, the number it returns is 5.29 instead of the root between 4 and 8 which is 6.9025.
Is there something wrong with my code or am I just not understanding the false position method correctly?
You should use Double for precision with Maths problems. Three other notes about coding that you may not be aware of:
dim a, b, c as Single
will dim a and b as Variants, and c as a Single, and you can use Exit For to escape from a for loop, rather than setting the control variable out of the bounds. Finally, you should define the outputs of a Function by specifying As ... after the closing parenthesis.
You should use breakpoints (press F9 with the carrot in a line of code to breakpoint that line), then step through the code by pressing F8 to advance line-by-line to see what is happening, and keep your eye on the Locals window (Go to View > Locals)
This is the code with the above changes:
Function Func(x As Double) As Double
Func = (x ^ (1.5 * Sin(x))) * Exp(-x / 7) + Exp(x / 10) - 4
End Function
Function FalsePos(Guess1 As Double, Guess2 As Double) As Double
Dim a As Double, b As Double, c As Double
Dim i As Integer
a = Guess1
b = Guess2
For i = 0 To 1000
c = a - Func(a) * (b - a) / (Func(b) - Func(a))
If (Func(c) < 0.00001) Then
Exit For
Else
If Func(a) * Func(c) < 0 Then
b = c
Else
a = c
End If
End If
Next
FalsePos = c
End Function
I have a sequence of numbers as follows:
1 , 1, 5, 13, 41, 121, 365, ....
The first two values are:
N(1) = 1 and N(2) = 1
As from 3rd value, N(i) = 2*N(i-1) + 3*N(i-2)
The issue I am facing with is: If I give an argument of p, it should return me the last values of the sequence < p (Using fortran77).
For instance, if p = 90, it should return the value 41.
a = 1
b = 1
while b < p:
c = 2 * b + 3 * a
a = b
b = c
return a
The Fortran equivalent is:
function fct(p) result(a)
integer, intent(in) :: p
integer :: a, b, c
a = 1
b = 1
do while (b < p)
c = 2 * b + 3 * a
a = b
b = c
enddo
end function
program test
integer :: fct
external fct
print *,fct(90)
end program
Assuming you already have the sequence in a variable lst, and p set,
max(filter(lambda x:x<=p, lst))
def get_last_element(p):
n1 = 1
n2 = 1
while True:
if n2 > p:
return n1
n1, n2 = n2, 2*n2 + 3 * n1
print(get_last_element(90))
I wrote a piece of code in Fortran 2003. I defined a type which has memory for two last parts of the sequence.The procedure is a recursive function. The type can be used standalone to get n-th part of the sequence or efficiently placed in a loop to find parts in a row (not necessarily beginning at 1) as it has memory of previous parts. (compiler: gfortran 4.8).
The type is defined in mymod.f90 file as
module mymod
implicit none
type seq_t
integer :: saved_i = 0, saved_val_i = 0, saved_val_i_1 = 0
contains
procedure :: getpart => getpart_seq
end type
contains
recursive function getpart_seq(this,i) result(r)
class(seq_t) :: this
integer, intent(in) :: i
integer :: r,r_1,r_2
if (i.eq.1.or.i.eq.2) then
r = 1
elseif(i.eq.this%saved_i) then
r = this%saved_val_i
elseif(i.eq.this%saved_i-1) then
r = this%saved_val_i_1
else
r_1 = this%getpart(i-1)
r_2 = this%getpart(i-2)
r = 2*r_1 + 3*r_2
this%saved_val_i_1 = r_1
end if
this%saved_i = i
this%saved_val_i = r
end function getpart_seq
end module mymod
The main program for the requested case is
program main
use mymod
implicit none
type (seq_t) :: seq
integer :: i,p,tmp_new,tmp_old,ans
! Set the threshold here
p = 90
! loop over parts of the sequence
i = 0
do
i = i + 1
tmp_new = seq%getpart(i)
print*,tmp_new
if (tmp_new>p) then
ans = tmp_old
exit
end if
tmp_old = tmp_new
end do
print*,"The last part of sequence less then",p," is equal to",ans
end program
The outcome is
1
1
5
13
41
121
The last part of sequence less then 90 is equal to 41.
I have 4 strings in variables a,b,c and d. I need to randomly order these variables in such a way so that I can input them into 4 different text boxes but not the same ones every time the program is ran.
I've tried to simplify it for myself by putting the strings into an array. Tell me what I'm doing wrong or if there's a way I could do it much easier.
Private Sub Random()
For i = 1 To 4
If a = 0 Then
a = r.Next(2, 5)
ElseIf b = 0 Then
Do Until b <> a
b = r.Next(2, 5)
Loop
ElseIf c = 0 Then
Do Until c <> a Or c <> b
c = r.Next(2, 5)
Loop
ElseIf d = 0 Then
Do Until d <> a Or d <> b Or d <> c
d = r.Next(2, 5)
Loop
End If
Next
End Sub
Here is one way to do it:
Dim a As String = "a"
Dim b As String = "b"
Dim c As String = "c"
Dim d As String = "d"
Dim all As String() = {a, b, c, d}
Dim random As New Random
Dim allRandom As String() = all.OrderBy(Function() random.Next).ToArray
I have the following code:
Sub Main()
Dim a As Integer = 8 * 60
Dim b As Integer
Dim c As Integer
If a < (6 * 60) Then
b = 0 And c = 0
ElseIf a >= 6 * 60 And a < 9 * 60 Then
b = 30 And c = 1
Else
b = 45 And
c = 1
End If
MsgBox(b)
End Sub
Thinks i dont understand and where i need someones help:
"c=0" and "c=1" are underlined with the error: Strict on doesnt allow implicit convertation from boolean to integer. WHY? I declared c as integer!
Variable "b" and "c" are always "0" even though in the case above they should be b=30 and c = 1.
can anyone please explain me this behaviour.
You are using the And keyword where it is not allowed. And is a logical operator (along with Or, AndAlso, OrElse.)
The following should work.
Sub Main()
Dim a As Integer = 8 * 60
Dim b As Integer
Dim c As Integer
If a < (6 * 60) Then
b = 0
c = 0
ElseIf a >= 6 * 60 And a < 9 * 60 Then
b = 30
c = 1
Else
b = 45
c = 1
End If
MsgBox(b)
End Sub
I am still new to vba.
I am trying to create a new function however, it keeps giving me an output that I am not expecting.
my code is as follows:
Function bonusplanA(a, b, c)
Dim example As Range
Set example = Range("a:c")
Value = Application.WorksheetFunction.CountIf(example, ">=90")
Value1 = Application.WorksheetFunction.CountIf(example, ">=80")
If Value = 3 Then
bonusplanA = "$20,000 bonus"
Else
If Value1 = 3 Then
bonusplanA = "$10,000 bonus"
Else
bonusplanA = "NO BONUS"
End If
End If
End Function
You need to define your function like this:
Function bonusplanA(a, b, c)
If a >= 90 And b >= 90 And c >= 90 Then
bonusplanA = "$20,000 bonus"
Else
If a >= 80 And b >= 80 And c >= 80 Then
bonusplanA = "$10,000 bonus"
Else
bonusplanA = "NO BONUS"
End If
End If
End Function
The problem in your example was that Range("a:c") does not make a range of your a,b,c variables; instead it selects the range composed of columns A, B and C.
You need to use parameters a, b and c directly, not through the Range function.
Otherwise, the logic was sound. :)