How can I make all the numbers that come up be rounded to 2 decimal places? What should I write in class level so that I don't have to write Math.Round(var, 2) a hundred times?
You can’t control this on the class level, nor should you.
You should control it where ever you output the numbers. But of course you don’t need to (and shouldn’t) repeat code over and over again: you can just make all output code call the same function.
Furthermore, you should not use Math.Round, and especially not in every computation (that will yield wrong results!). Instead, use String.Format to get the correct textual representation of your numbers, where you output them:
Shared Function Representation(number As Double) As String
Return number.ToString("#.##")
End Function
Related
I'm trying to write a function of this form:
Function cont(requestdate As Date)
cont = requestdate
End Function
Unfortunately, when I enter =cont(12/12/2012) into a cell, I do not get my date back. I get a very small number, which I think equals 12 divided by 12 divided by 2012. How can I get this to give me back the date? I do not want the user to have to enter =cont("12/12/2012").
I've attempted to google for an answer, unfortunately, I have not found anything helpful. Please let me know if my vocabulary is correct.
Let's say my user pulled a report with 3 columns, a, b and c. a has beginning of quarter balances, b has end of quarter balances and c has a first and last name. I want my user to put in column d: =cont(a1,b1,c1,12/12/2012) and make it create something like:
BOQ IS 1200, EOQ IS 1300, NAME IS EDDARD STARK, DATE IS 12/12/2012
So we could load this into a database. I apologize for the lack of info the first time around. To be honest, this function wouldn't save me a ton of time. I'm just trying to learn VBA, and thought this would be a good exercise... Then I got stuck.
Hard to tell what you are really trying to accomplish.
Function cont(requestdate As String) As String
cont = Format(Replace(requestdate, ".", "/"), "'mm_dd_YYYY")
End Function
This code will take a string that Excel does not recognize as a number e.g. 12.12.12 and formats it (about the only useful thing I can think of for this UDF) and return it as a string (that is not a number or date) to a cell that is formatted as text.
You can get as fancy as you like in processing the string entered and formatting the string returned - just that BOTH can never be a number or a date (or anything else Excel recognizes.)
There is no way to do exactly what you're trying to do. I will try to explain why.
You might think that because your function requires a Date argument, that this somehow forces or should force that 12/12/2012 to be treated as a Date. And it is treated as a Date — but only after it's evaluated (only if the evaluated expression cannot be interpreted as a Date, then you will get an error).
Why does Excel evaluate this before the function receives it?
Without requiring string qualifiers, how could the application possibly know what type of data you intended, or whether you intended for that to be evaluated? It could not possibly know, so there would be chaos.
Perhaps this is best illustrated by example. Using your function:
=Cont(1/1/0000) should raise an error.
Or consider a very simple formula:
=1/2
Should this formula return .5 (double) or January 2 (date) or should it return "1/2" (string literal)? Ultimately, it has to do one of these, and do that one thing consistently, and the one thing that Excel will do in this case is to evaluate the expression.
TL;DR
Your problem is that unqualified expression will be evaluated before being passed, and this is done to avoid confusion or ambiguity (per examples).
Here is my method for allowing quick date entry into a User Defined Function without wrapping the date in quotes:
Function cont(requestdate As Double) As Date
cont = CDate((Mid(Application.Caller.Formula, 7, 10)))
End Function
The UDF call lines up with the OP's initial request:
=cont(12/12/2012)
I believe that this method would adapt just fine for the OP's more complex ask, but suggest moving the date to the beginning of the call:
=cont(12/12/2012,a1,b1,c1)
I fully expect that this method can be optimized for both speed and flexibility. Working on a project now that might require me to further dig into the speed piece, but it suits my needs in the meantime. Will update if anything useful turns up.
Brief Explanation
Application.Caller returns a Range containing the cell that called the UDF. (See Caveat #2)
Mid returns part of a string (the formula from the range that called the UDF in this case) starting at the specified character count (7) of the specified length (10).
CDate may not actually be necessary, but forces the value into date format if possible.
Caveats
This does require use of the full dd/mm/yyyy (1/1/2012 would fail) but pleasantly still works with my preferred yyyy/mm/dd format as well as covering some other delimiters. dd-mm-yyyy or dd+mm+yyyy would work, but dd.mm.yyyy will not because excel does not recognize it as a valid number.
Additional work would be necessary for this to function as part of a multi-cell array formula because Application.Caller returns a range containing all of the associated cells in that case.
There is no error handling, and =cont(123) or =cont(derp) (basically anything not dd/mm/yyy) will naturally fail.
Disclaimers
A quick note to the folks who are questioning the wisdom of a UDF here: I've got a big grid of items and their associated tasks. With no arguments, my UDF calculates due dates based on a number of item and task parameters. When the optional date is included, the UDF returns a delta between the actual date and what was calculated. I use this delta to monitor and calibrate my calculated due dates.
All of this can absolutely be performed without the UDF, but bulk entry would be considerably more challenging to say the least.
Removing the need for quotes sets my data entry up such that loading =cont( into the clipboard allows my left hand to F2/ctrl-v/tab while my right hand furiously enters dates on the numpad without need to frequently (and awkwardly) shift left-hand position for a shift+'.
I'm using VB.NET, writing a winforms application where I'm trying to convert from a denary real number to a signed floating point binary number, as a string representation. For example, 9.125 would become "0100100100000100" (the first ten digits are the significand and the last six digits the exponent.).
I can write a function for this if I have to, but I'd rather not waste time if there's a built-in functionality available. I know there's some ToString overload or something that works on Integers, but I haven't been able to find anything that works on Doubles.
I need to store an alphanumeric string in an integer column on one of my models.
I have tried:
#result.each do |i|
hex_id = []
i["id"].split(//).each{|c| hex_id.push(c.hex)}
hex_id = hex_id.join
...
Model.create(:origin_id => hex_id)
...
end
When I run this in the console using puts hex_id in place of the create line, it returns the correct values, however the above code results in the origin_id being set to "2147483647" for every instance. An example string input is "t6gnk3pp86gg4sboh5oin5vr40" so that doesn't make any sense to me.
Can anyone tell me what is going wrong here or suggest a better way to store a string like the aforementioned example as a unique integer?
Thanks.
Answering by request form OP
It seems that the hex_id.join operation does not concatenate strings in this case but instead sums or performs binary complement of the hex values. The issue could also be that hex_id is an array of hex-es rather than a string, or char array. Nevertheless, what seems to happen is reaching the maximum positive value for the integer type 2147483647. Still, I was unable to find any documented effects on array.join applied on a hex array, it appears it is not concatenation of the elements.
On the other hand, the desired result 060003008600401100500050040 is too large to be recorded as an integer either. A better approach would be to keep it as a string, or use different algorithm for producing a number form the original string. Perhaps aggregating the hex values by an arithmetic operation will do better than join ?
I was looking for a way to enumerate String types in (vb).NET, but .NET enums only accept numeric type values.
The first alternative I came across was to create a dictionary of my enum values and the string I want to return. This worked, but was hard to maintain because if you changed the enum you would have to remember to also change the dictionary.
The second alternative was to set field attributes on each enum member, and retrieve it using reflection. Surely enough this worked aswell and also solved the maintenance problem, but it uses reflection and I've always read that using reflection should be a last resort thing.
So I started thinking and I came up with this: every ASCII character can be represented as a hexadecimal value, and you can assign hexadecimal values to enum members.
You could get rid of the attributes, assign the hexadecimal values to the enum members. Then, when you need the text value, convert the value to a byte array and use System.Text.Encodings.ASCII.GetString(enumMemberBytes) to get the string value.
Now speaking out of experience, anything I come up with is usually either flawed or just plain wrong. What do you guys think about this approach? Is there any reason not to do it like that?
Thanks.
EDIT
As pointed out by David W, enum member values are limited in length, depending on the underlying type (integer by default). So yes, I believe my method works but you are limited to characters in the ASCII table, with a maximum length of 4 or 8 characters using integers or longs respectively.
The easiest way I have found to dynamically parse a String representation of an Enumeration into the actual Enumeration type was to do the following:
Private EnumObject
[Undefined]
ValueA
ValueB
End Enum
dim enumVal as EnumObject = DirectCast([Enum].Parse(GetType(EnumObject), "ValueA"), EnumObject)
This removes the need to maintain a dictionary and allows you to just handle strings instead of converting to an Int or a Long. This does use reflection, but I have not come across any issues as long as you catch and handle any exceptions with the String Parse.
having a bit of trouble finding a solution to this.
I want to take a large ordered text file of words and create - in the same order - a text file of fixed length numeric values.
For example:
Input File Output File
AAA -> 00000001
AAH -> 00002718
AAZ -> 71827651
Initially it seemed a hash function would do the trick. However they are one way. Also perhaps they are a bit "heavyweight" for this. After all, I don't need any cryptography. Plus, it's a reference file. It will never change.
Any compression is a bonus not essential. That said, I don't want the file to get any bigger than it already is. Which is why I don't just want to write out the words as text but with fixed lengths.
So, bottom line; input is a NSString of variable length, output is an integer of fixed length. And, I must be able to take the integer and figure out the string.
Any help much appreciated!
Thanks!
xj
Well, this would be a bit of a brute force method, but here's my guess.
Start by making a custom function to convert one letter of text to an integer less than 100. (I'm not sure if such a function already exists, if so then great!) You might need to just go to stuff like "if ([input isEqual: #"a"]){ return 1;}
Then, run that function on each letter of text, and get the final integer by combining the previous results.
For example:
int myVal1 = [intConverter firstLetter];
int myVal2 = [intConverter secondLetter];
int myVal3 = [intConverter thirdLetter];
int finalValue =100^3 + 100^2*myVal1 + 100*myVal2 + myVal3;
Then, finalValue would be of the form 1(myVal1)(myVal2)(myVal3), which is what I think you're looking for.
To get back the original string, simply use the mod (%) and division functions to get the individual values back, then run the intConverter function backwards. (This would probably mean writing a new function that basically runs those if statements in reverse, but oh well.)
I hope this helps.