I don't know how to read VBA (excel). Can you help me and translate this function?
Function calculateDigit(value)
lenval = Len(value)
factor = 3
Sum = 0
For Index = lenval To 1 Step -1
Sum = Sum + (CInt(Mid(value, Index, 1)) * factor)
factor = 4 - factor
Next
calculateDigit = ((1000 - Sum) Mod 10)
End Function
My problem is simple.
I am searching a mathematical function to distribute number over an interval.
For example I have this list :
[2; 4; 9; 14]
And in my case I wish
2 -> 1 = f(2)
14 -> 20 = f(14)
4 -> f(4) = ?
9 -> f(9) = ?
This is just an example I am searching for f(x).
Someone would have any idea ?
Thanks for advance ! :)
If you want a linear function, then:
f(x) = lowerFunc + (x - lowerX) * (upperFunc - lowerFunc) / (upperX - lowerX),
where:
lowerFunc: function value at the lower end
upperFunc: function value at the upper end
lowerX: x parameter at the lower end
upperX: x parameter at the upper end.
For your example:
f(x) = 1 + (x - 2) * (20 - 1) / (14 - 2)
= 1 + (x - 2) * 19/12
f(2) = 1
f(4) = 4.1666
f(9) = 12.08333
f(14) = 20
I'm trying to encode some strings in my lua script, and since that I have a lua script with over 200k characters, encrypting each string query in the script with a function such as this example below
local string = "stackoverflow"
local string = [[stackoverflow]]
local string = [==[stackoverflow]==]
local string = 'stackoverflow'
to
local string=decode("jkrtbfmviwcfn",519211)
Trying to provide all above results to thread through a gsub and have the gsub encode the string text with a random offset number.
So far, I was only capable of gsubbing full quotation marks through.
function encode(x,offset,a)
for char in string.gmatch(x, "%a") do
local encrypted = string.byte(char) + offset
while encrypted > 122 do
encrypted = encrypted - 26
end
while encrypted < 97 do
encrypted = encrypted + 26
end
a[#a+1] = string.char(encrypted)
end
return table.concat(a)
end
luacode=[==[thatstring.Value="Encryptme!" testvalue.Value=[[string with
a linebreak]] string.Text="STOP!"]==]
luacode=luacode:gsub([=["(.-)"]=],function(s)
print("Caught "..s)
local offset=math.random(1,4)
local encoded=encode(s,offset,{})
return [[decode("]]..encoded..[[",]]..offset..[[)]]
end)
print("\n"..luacode)
With its output being
Caught Encryptme!
Caught STOP!
thatstring.Value=decode("crgvctxqi",4) testvalue.Value=[[string with
a linebreak]] string.Text=decode("opkl",2)
Any better solutions?
local function strings_and_comments(lua_code, callback)
-- lua_code must be valid Lua code (an error may be raised on syntax error)
-- callback will be invoked as callback(object_type, value, start_pos, end_pos)
-- callback("comment", comment_text, start_pos, end_pos) -- for comments
-- callback("string", string_value, start_pos, end_pos) -- for string literals
local objects = {} -- possible comments and string literals in the code
-- search for all start positions of comments (with false positives)
for pos, br1, eq, br2 in lua_code:gmatch"()%-%-(%-*%[?)(=*)(%[?)" do
table.insert(objects, {start_pos = pos,
terminator = br1 == "[" and br2 == "[" and "]"..eq.."]" or "\n"})
end
-- search for all start positions of string literals (with false positives)
for pos, eq in lua_code:gmatch"()%[(=*)%[[%[=]*" do
table.insert(objects, {is_string = true, start_pos = pos,
terminator = "]"..eq.."]"})
end
for pos, quote in lua_code:gmatch"()(['\"])" do
table.insert(objects, {is_string = true, start_pos = pos, quote = quote})
end
table.sort(objects, function(a, b) return a.start_pos < b.start_pos end)
local end_pos = 0
for _, object in ipairs(objects) do
local start_pos, ok, symbol = object.start_pos
if start_pos > end_pos then
if object.terminator == "\n" then
end_pos = lua_code:find("\n", start_pos + 1, true) or #lua_code
-- exclude last spaces and newline
while lua_code:sub(end_pos, end_pos):match"%s" do
end_pos = end_pos - 1
end
elseif object.terminator then
ok, end_pos = lua_code:find(object.terminator, start_pos + 1, true)
assert(ok, "Not a valid Lua code")
else
end_pos = start_pos
repeat
ok, end_pos, symbol = lua_code:find("(\\?.)", end_pos + 1)
assert(ok, "Not a valid Lua code")
until symbol == object.quote
end
local value = lua_code:sub(start_pos, end_pos):gsub("^%-*%s*", "")
if object.terminator ~= "\n" then
value = assert((loadstring or load)("return "..value))()
end
callback(object.is_string and "string" or "comment", value, start_pos, end_pos)
end
end
end
local inv256
local function encode(str)
local seed = math.random(0x7FFFFFFF)
local result = '",'..seed..'))'
if not inv256 then
inv256 = {}
for M = 0, 127 do
local inv = -1
repeat inv = inv + 2
until inv * (2*M + 1) % 256 == 1
inv256[M] = inv
end
end
repeat
seed = seed * 3
until seed > 2^43
local K = 8186484168865098 + seed
result = '(decode("'..str:gsub('.',
function(m)
local L = K % 274877906944 -- 2^38
local H = (K - L) / 274877906944
local M = H % 128
m = m:byte()
local c = (m * inv256[M] - (H - M) / 128) % 256
K = L * 21271 + H + c + m
return ('%02x'):format(c)
end
)..result
return result
end
function hide_strings_in_lua_code(lua_code)
local text = { [[
local function decode(str, seed)
repeat
seed = seed * 3
until seed > 2^43
local K = 8186484168865098 + seed
return (str:gsub('%x%x',
function(c)
local L = K % 274877906944 -- 2^38
local H = (K - L) / 274877906944
local M = H % 128
c = tonumber(c, 16)
local m = (c + (H - M) / 128) * (2*M + 1) % 256
K = L * 21271 + H + c + m
return string.char(m)
end
))
end
]] }
local pos = 1
strings_and_comments(lua_code,
function (object_type, value, start_pos, end_pos)
if object_type == "string" then
table.insert(text, lua_code:sub(pos, start_pos - 1))
table.insert(text, encode(value))
pos = end_pos + 1
end
end)
table.insert(text, lua_code:sub(pos))
return table.concat(text)
end
Usage:
math.randomseed(os.time())
-- This is the program to be converted
local luacode = [===[
print"Hello world!"
print[[string with
a linebreak]]
local str1 = "stackoverflow"
local str2 = [[stackoverflow]]
local str3 = [==[stackoverflow]==]
local str4 = 'stackoverflow'
print(str1)
print(str2)
print(str3)
print(str4)
]===]
-- Conversion
print(hide_strings_in_lua_code(luacode))
Output (converted program)
local function decode(str, seed)
repeat
seed = seed * 3
until seed > 2^43
local K = 8186484168865098 + seed
return (str:gsub('%x%x',
function(c)
local L = K % 274877906944 -- 2^38
local H = (K - L) / 274877906944
local M = H % 128
c = tonumber(c, 16)
local m = (c + (H - M) / 128) * (2*M + 1) % 256
K = L * 21271 + H + c + m
return string.char(m)
end
))
end
print(decode("ef869b23b69b7fbc7f89bbe7",2686976))
print(decode("c2dc20f7061c452db49302f8a1d9317aad1009711e0984",1210253312))
local str1 = (decode("84854df4599affe9c894060431",415105024))
local str2 = (decode("a5d7db792f0b514417827f34e3",1736704000))
local str3 = (decode("6a61bcf9fd6f403ed1b4846e58",1256259584))
local str4 = (decode("cad56d9dea239514aca9c8b8e0",1030488064))
print(str1)
print(str2)
print(str3)
print(str4)
Output of output (output produced by the converted program)
Hello world!
string with
a linebreak
stackoverflow
stackoverflow
stackoverflow
stackoverflow
I got some code written in a function in VBA, but I'm stuck on how to return the output values areaAnswer1 & areaAnswer2 inside the if - else statments. I'm still new to this. Any help & suggestions are very much appreciated.
Function dateArea(inputDate1 As Date, t1 As Date, t2 As Date, duration As Integer, output As Integer) As Integer
endOfYear = Workbook.Date(Year(inputDate1), 12, 31)
inputDate2 = Workbook.Date(Year(inputDate1) + 1, Month(inputDate1), Day(inputDate1))
endOfDate1 = Workbook.Date(Year(inputDate1) + duration, Month(inputDate1), Day(inputDate1))
endOfDate2 = Workbook.Date(Year(inputDate2) + duration, Month(inputDate2), Day(inputDate2))
areaBase1 = endOfYear - inputDate1
areaBase2 = inputDate2 - endOfYear
totalArea1 = areaBase1 * 365
totalArea2 = areaBase2 * 365
triangleBase1 = endOfDate1 - inputDate1
triangleHypo1 = Workbook.Sqrt((365 * 365) + (triangleBase1 * triangleBase1))
triangleBase2 = t1 - inputDate2
triangleHypo2 = triangleHypo1 * triangleBase2 / triangleBase1
triangleHeight2 = Workbook.Sqrt((triangleHypo2 * triangleHypo2) - (triangleBase2 * triangleBase2))
triangleArea2 = (triangleBase2 * triangleHeight2) / 2
triangleBase3 = (inputDate2 - endOfYear) + (t1 - inputDate2)
triangleHypo3 = triangleBase3 * triangleHypo2 / (t1 - inputDate2)
triangleHeight3 = Workbook.Sqrt((triangleHypo3 * triangleHypo3) - (triangleBase3 * triangleBase3))
triangleArea3 = (triangleBase3 * triangleBaseHeight3) / 2
areaDiffBot2 = triangleArea3 - triangleArea2
triangleBase4 = 365 + (t1 - inputDate2)
triangleHypo4 = triangleBase4 * triangleHeight2 / (t1 - inputDate2)
triangleHeight4 = Workbook.Sqrt((triangleHypo4 * triangleHypo4) - (triangleBase4 * triangleBase4))
triangleArea4 = (triangleBase4 * triangleHeight4) / 2
areaDiffBot1 = triangleArea4 - triangleArea3
triangleHeight5 = 365 * (endOfDate1 - t2) / triangleBase1
triangleHypo5 = Workbook.Sqrt((triangleHeight5 * triangleHeight5) + ((endOfDate1 - t2) * (endOfDate1 - t2)))
triangleArea5 = (endOfDate1 - t2) * triangleHeight5 / 2
triangleBase6 = (endOfDate1 - t2) + areaBase1
triangleHeight6 = (triangleBase6) * 365 / (endOfDate1 - t2)
triangleHypo6 = Workbook.Sqrt((triangleBase6 * triangleBase6) + (triangleHeight6 * triangleHeight6))
triangleArea6 = (triangleBase6 * triangleHeight6) / 2
areaDiffTop1 = triangleArea6 - triangleArea5
triangleBase7 = triangleBase6 + areaBase2
triangleHeight7 = triangleBase7 * triangleHeight6 / triangleBase6
triangleHypo7 = Workbook.Sqrt((triangleBase7 * triangleBase7) + (triangleHeight7 * triangleHeight7))
triangleArea7 = (triangleBase7 * triangleHeight7) / 2
areaDiffTop2 = triangleArea7 - triangleArea6
totalUsedArea1 = areaDiffTop1 + areaDiffBot1
totalUsedArea2 = areaDiffTop2 + areaDiffBot2
areaAnswer1 = totalArea1 - totalUsedArea1
areaAnswer2 = totalArea2 - totalUsedArea2
If output = 1 Then
ElseIf output = 2 Then
ElseIf output = 3 Then
Else
End If
End Function
In VBA you set the return value by assigning it to the function like this:
areaAnswer1 = totalArea1 - totalUsedArea1
areaAnswer2 = totalArea2 - totalUsedArea2
If output = 1 Then
dateArea = areaAnswer1
ElseIf output = 2 Then
dateArea = areaAnswer2
ElseIf output = 3 Then
' ...etc
Note that the assignment to the function does not exit the function. In this case you don't need that immediate exit, as you are already at the end of it. But in some cases you'll want to exit the function as soon as you have assigned the return value:
Exit Function
Just have the function equal a typed value or one of the variables at the end.
select case output
case 1
dateArea = totalUsedArea1
case 2
dateArea = totalUsedArea2
case 3
dateArea = totalUsedArea3
case else
'do something or nothing
end select
Note that you have specified returning an integer which cannot contain a decimal and must be smaller than 32667 (or there abouts).
I am trying to run this code to calculate Q(n) at different Tn in the Equation 16.4 in the attached picture.But its not giving me the correct output. I would appreciate any help. Note: delta1=delta2 =...deltan = dt=1 ( I have taken here ) and further divided S term by 10000 just because in the Equation it is in basis point i.e. 100th part of 1 %.
Function Bootstrap(S As Range, Z As Range, L As Double) As Double
Dim j As Integer
Dim a As Variant
Dim b As Variant
Dim n As Integer
Dim Q() As Double
Dim sum As Double
Dim P As Double
Dim dt As Double
n = Application.WorksheetFunction.Max(S.Columns.Count, Z.Columns.Count)
a = S.Value
b = Z.Value
dt = 1
sum = 0
ReDim Q(0 To n)
Q(0) = 1
For j = 1 To n - 1
P = (b(1, j) * (L * Q(j - 1) - (L + dt * a(1, n) / 10000) * Q(j))) / (b(1, n) * (L + a(1, n) * dt / 10000)) + Q(n - 1) * L / (L + a(1, n) * dt / 10000)
sum = sum + P
Q(n) = sum
Next j
Bootstrap = sum
End Function
To solve a recursive function you can write it this way, for example
Function Factorial(n as long) as long
If n = 1 Then
Factorial = 1
Else
Factorial = n * Factorial(n-1)
End If
End function
Yes, you can see For...Loop can also do the Factorial calculation, but in your case, its much easier to use recursive solution.
Besides Eq 16.4 is intentionally written as a recursive function. It is not written as a summation function because it is harder to do so. If given to you is a summation function, then you can apply the For...Loop solution.
Hope this helps.
EDIT
Function Q(n as long) as double
If n = 1 Then
Q = 5
Else
Q = Z * ( L * Q_t - (L + d * S) * Q(n-1) ) / ( Z * ( L + d * S ) )
End If
End Function
Notice that the function Q keep calling itself in Q(n-1) when n>1. That is called recursive solution.
(Check the formula. I might copy it wrong)