ok so im trying to do an assignment and i have written this code but it has errors, and i cant see why.
its saying expected statement, and im looking over it and i cant find what the problem is. Would be amazing if someone could shed some light on the error and possibly help me out.
here is the do until statement:
Sub btnTransformY_onclick()
Do Until r = 4 And n = 3
Do Until m = 1 To 8
Change(r,c) = (transformationY(r,1) * meh(1, m)) + transformationY(r, 2) * meh(2,m) + TransformationY(r,3) * meh(3,m)
m = m + 1
Next
c = c + 1
If c = 8 Then r = r + 1 And c = 1
Next
End Sub
unfortunately this hasnt worked, although it does seem to be the Do Until m = 1 To 8
does anyone know if to is valid syntax for a do until loop?
I reckon you want something on these lines, except I suspect you want two Next loops for r and n rather than one Do Until.
Sub btnTransformY_onclick()
r = 0
n = 0
Do Until r = 4 And n = 3
For m = 1 To 8
Change(r,c) = (transformationY(r,1) * meh(1, m)) + transformationY(r, 2) * meh(2,m) + TransformationY(r,3) * meh(3,m)
''m = m + 1
Next
c = c + 1
If c = 8 Then
r = r + 1
c = 1
''Where does n get counted up?
End If
Loop
End Sub
Next is for for loops, to close a do loop use loop:
do until ..
...
loop
Also
if c = 8 then r = r + 1 and c = 1
Is a bitwise comparison (bits of LHS anded with RHS) which is probably not what you want, so instead;
if c = 8 then
r = r + 1
c = 1
end if
Related
I have a pseudocode assignment for a class. I have to design a program to output every even number starting with 2 and going to 100. I need someone to tell me if this is correct. If it isn't could someone point me in the right direction?
start
Declarations
num A = 0
num B = 100
num C
while A < B
C = A + 2
Output C
Endwhile
stop
start
Declarations
num A = 0
num B = 100
while A < B
A = A + 2
Output A
Endwhile
stop
I'm trying to create a method converting a number to normalized scientific notation, here is the code that I'm using to calculate mantissa and exponent:
ConvNSN 1000, M, P
MsgBox M & "e" & P
Sub ConvNSN(N, M, P)
If N = 0 Then
P = 0
M = 0
Else
P = Int(Log(Abs(N)) / Log(10))
M = N / 10 ^ P
End If
End Sub
The problem I am facing is that this code gives wrong exponent value for some numbers, eg 1000, 10E+6, 10E+9, 10E+12, 10E+13, etc... Exactly for 1000 converted should be 1e3, but not 10e2. It's obvious that the same problem with numbers, whose logarithms are close to an integer value, like Log(1 - 5.55111512312578E-17) / Log(10), which result is 0, however 1 - 5.55111512312578E-17 less then 1, and result has to be negative.
How can I get rid of Double type imprecision, and get this code to work properly?
UPDATE
I assume the fastest and quite accurate method to calculate mantissa and exponent of number in normalized scientific notation may be as follows:
Sub ConvNSN(N, M, P)
Dim A
If N = 0 Then
P = 0
M = 0
Exit Sub
End If
A = Abs(N)
If A < 1 Then
P = Int(Log(A) / Log(10))
Else
P = Int(Log(A) / Log(10) * (2 + Log(.1) / Log(10)))
End If
M = N / 10 ^ P
End Sub
Or another one, based on #Bob's solution:
Sub ConvNSN(N, M, P)
If N = 0 Then
P = 0
M = 0
Else
P = Int(Log(Abs(N)) / Log(10))
M = N / 10 ^ P
End If
If Abs(M) = "10" Then
M = M / 10
P = P + 1
End If
End Sub
First one slightly faster. Both of them process exponent from -322 to 308, but return not normalized mantissa with powers of 10 less then -310. I have not tested them yet with numbers, whose logarithms are a marginally less but very close to an integer values.
UPDATE 2
I decided to attach here an extra Sub ConvEN(), allowing to represent a number in engineering notation with SI prefixes from "p" to "T":
N = .0000456789
ConvNSN N, M, P
M = Round(M, 2)
ConvEN M, P, R, S
MsgBox R & " " & S & "Units"
Sub ConvNSN(N, M, P)
Dim A
If N = 0 Then
P = 0
M = 0
Exit Sub
End If
A = Abs(N)
If A < 1 Then
P = Int(Log(A) / Log(10))
Else
P = Int(Log(A) / Log(10) * (2 + Log(.1) / Log(10)))
End If
M = N / 10 ^ P
End Sub
Sub ConvEN(M, P, R, S)
DIM Q, P3
Q = int(P / 3)
P3 = Q * 3
If Q >= -4 And Q <= 4 Then
S = Array("p", "n", ChrW(&H03BC), "m", "", "k", "M", "G", "T")(Q + 4)
Else
S = "e" & P3 & " "
End If
R = M * 10 ^ (P - P3)
End Sub
Try this:
ConvNSN 1000, M, P
MsgBox M & "E" & P
ConvNSN 0.00000000000000001234, M, P
MsgBox M & "E" & P
ConvNSN -0.00000000000000001234, M, P
MsgBox M & "E" & P
Sub ConvNSN(N, M, P)
P = 0
If N < 0 Then
S = -1
ElseIf N > 0 Then
S = 1
Else
M = 0
Exit Sub
End If
M = Abs(N)
If M >= 10 Then
While M >= 10
M = M / 10
P = P + 1
Wend
M = M * S
Exit Sub
End If
If M < 1 Then
While M < 1
M = M * 10
P = P - 1
Wend
M = M * S
Exit Sub
End If
End Sub
Based on the comments, I re-wrote this my way, ignoring the structure from the OP.
MsgBox NSN(-0.0000000000000000000123456789,4)
MsgBox NSN(1234567890000000000000000000,4)
Function NSN(Number, Accuracy)
Exponent = 0
If Number > 0 Then
Sign = 1
ElseIf Number < 0 Then
Sign = -1
Else
NSN = 0
Exit Function
End If
Number = Number * Sign
If Number >= 10 Then
While Number >= 10
Number = Number / 10
Exponent = Exponent + 1
Wend
ElseIf Number < 1 Then
While Number < 1
Number = Number * 10
Exponent = Exponent - 1
Wend
End If
Number = Round(Number, Accuracy)
If Number = "10" Then
Number = 1
Exponent = Exponent + 1
End If
Number = Number * Sign
If Exponent = 0 Then
NSN = Number
Else
NSN = Number & "E" & Exponent
End If
End Function
Using strings rather than maths can help. Add your own error checking.
Num = "1000000.0005"
NumOfDigits = 4
Mag = Instr(Num, ".")
Num = Replace(Num, ".", "")
MSD = Left(Num, 1)
Rest = Mid(num, 2, NumOfDigits)
msgbox MSD & "." & Rest & " x 10^" & (Mag -2)
How to sum 2 numbers digit by digit with pseudo code?
Note: You don't know the length of the numbers - if it has tens, hundreds, thousands...
Units should be add to units, tens to tens, hundreds to hundreds.....
If there is a value >= 10 in adding the units you need to put the value of that ten with "the tens"....
I tried
Start
Do
Add digit(x) in A to Sum(x)
Add digit(x) in B to Sum(x)
If Sum(x) > 9, then (?????)
digit(x) = digit(x+1)
while digit(x) in A and digit(x) in B is > 0
How to show the result?
I am lost with that.....
Please help!
Try this,
n = minDigit(a, b) where a and b are the numbers.
let sum be a number.
m = maxDigit(a,b)
allocate maxDigit(a,b) + 1 memory for sum
carry = 0;
for (i = 1 to n)
temp = a[i] + b[i] + carry
// reset carry
carry = 0
if (temp > 10)
carry = 1
temp = temp - 10;
sum[i] = temp
// one last step to get the leftover carry
if (digits(a) == digits(b)
sum[n + 1] = carry
return
if (digits(a) > digits(b)
toCopy = a
else
toCopy = b
for (i = n to m)
temp = toCopy[i] + carry
// reset carry
carry = 0
if (temp > 10)
carry = 1
temp = temp - 10;
sum[i] = temp
Let me know if it helps
A and B are the integers you want to sum.
Note that the while loop ends when all the three integers are equal to zero.
carry = 0
sum = 0
d = 1
while (A > 0 or B > 0 or carry > 0)
tmp = carry + A mod 10 + B mod 10
sum = sum + (tmp mod 10) * d
carry = tmp / 10
d = d * 10
A = A / 10
B = B / 10
For a school's assignment I am trying to calculate pi using the Gauss Legendre algorithm to test cpu efficiency.
Therefore, I have written a program in Ruby.
This program should iterate 500000000 times and display the the time used for it. But everytime it executes within a second.
My question:
Is there a better way to iterate so it really does repeat 500 million times and display pi and the time?
include Math
a = 1
b = 1/sqrt(2)
t = 0.25
p = 1
i = 0
imax = 500000000
start = Time.now
until i = imax
an = (a/2) + (b/2)
bn = sqrt(a) * sqrt(b)
tn = t - p * ((a-an) * (a-an))
pn = 2 * p
a = an
b = bn
t = tn
p = pn
i +=1
PI = ((a+b)*(a+b))/(4*t)
end
finish = Time.now
time = finish - start
puts PI
puts time
Start by not making i equal imax right away:
until i = imax
Should be
until i == imax
Even better, just do
500000000.times do
Instead of that line.
In addition to the issues raised by #Nick and #sawa your algorithm is flawed: the square root of the product of a and b is not equal to the product of the square roots of a and b.
In ruby:
include Math
a, b, t, p = 1, 1/sqrt(2), 0.25, 1
imax = 5
imax.times do |i|
an = (a+b) / 2
bn = sqrt(a * b)
tn = t - p * ((a-an) * (a-an))
pn = 2 * p
a, b, t, p = an, bn, tn, pn
pi = ((a+b)*(a+b))/(4*t)
printf "%d : %10.60f\n", i, pi
end
Running this gives me:
0 : 3.140579250522168575088244324433617293834686279296875000000000
1 : 3.141592646213542838751209274050779640674591064453125000000000
2 : 3.141592653589794004176383168669417500495910644531250000000000
3 : 3.141592653589794004176383168669417500495910644531250000000000
4 : 3.141592653589794004176383168669417500495910644531250000000000
So clearly you need more accuracy, hence BigDecimal. As this is your homework assignment I'll leave that up to you :-). (If unsure which variables to change, try all except i and imax. Also check out http://www.ruby-doc.org/stdlib-1.9.3/libdoc/bigdecimal/rdoc/BigDecimal.html)
Another thing you are doing wrong is assigning a constant PI within a loop. Although it is possible to reassign a constant, it is not correct to do so. Either use a variable or move the assignment to outside of the loop so that it would be assigned only once.
Even if I remove the assignment and print out the result for each iteration like this:
include Math
a = 1
b = 1/sqrt(2)
t = 0.25
p = 1
i = 0
imax = 500000000
until i == imax
an = (a/2) + (b/2)
bn = sqrt(a) * sqrt(b)
tn = t - p * ((a-an) * (a-an))
pn = 2 * p
a = an
b = bn
t = tn
p = pn
i +=1
puts ((a+b)*(a+b))/(4*t)
end
I get the wrong result. It goes like this:
-2.1244311544725596
-1.1383928808463357
-1.1265990444799223
-1.1265961703346379
-1.126596170334544
-1.126596170334544
... # very long repetition of the same number
-1.126596170334544
-1.126596170334544
NaN
NaN
... # NaN forever
Something must be wrong with your algorithm.
I'm developing a program in visual basic 6.0 to display magic square. I've developed the logic, but the values are not getting displayed in the magic square. Here's the code :
Private Sub Command1_Click()
Dim limit As Integer
Dim a(100, 100) As Integer
limit = InputBox("Enter the limit")
If limit Mod 2 = 0 Then ' Rows and columns must be
MsgBox "Can't be done", vbOKCancel, "Error"
Else ' set number of rows and columns to limit
mfgsquare.Rows = limit
mfgsquare.Cols = limit
j = (n + 1) / 2
i = 1
For c = 1 To n * n
mfgsquare.TextMatrix(i, j) = c
If c Mod n = 0 Then
i = i + 1
GoTo label
End If
If i = 1 Then
i = n
Else
i = i - 1
End If
If j = n Then
j = 1
Else
j = j + 1
End If
label:
Next c
End If
End Sub
Try this:
n = InputBox("Enter the limit")
If n Mod 2 = 0 Then ' Rows and columns must be
MsgBox "Can't be done"
Else ' set number of rows and columns to limit
mfgsquare.Rows = n + 1
mfgsquare.Cols = n + 1
For i = 1 To n
For j = 1 To n
mfgsquare.TextMatrix(i, j) = n * ((i + j - 1 + Int(n / 2)) Mod n) + ((i + 2 * j - 2) Mod n) + 1
Next j
Next i
End If