I store a formula in the database such as the following:GrossIncome+(Overtime/0.5)-Deductions=BasicNetIncome
I am able to substitute the string representations with actually values entered, thus:1000+(150*0.5)-100=BasicNetIncome
Then I remove the '=BasicNetIncome', thus:
1000+(150*0.5)-100
How can evaluate the above equation to return a result:
[Code]...
At the moment I'm in the process of building a class that can handle more advanced mathematical equations and processes. Essentially my end goal is to to have my class capable of processing anything you'd learn in Elementary Algebra through College Algebra. So far I am able to multiply monomials and order polynomials.. However for the most part the equations in questioned being processed have to be in correct form. IE Point-Slope Form, Y-Intercept Form, etc etc. I'm just curious as to how I can go about "validating an equation type by it's current form".
View 5 RepliesIn our school theres a programming class and the teachers gone for the week and the sub is starting to get very frustrated, so I offered to help in any way i can. I have never programmed Visual Basic but I have programmed Ms-Dos, Javascript, HTML, *.vbs, *.ahk, *.gml, and a variety of other languages.
The class is going to build a program that calculate how many rabbits are born in a family. So when they click the button it shows in a text box the actual equation and then the answer after the equal sign that where i assume concatenation comes in.Here's the code I've thrown together for when the buttons pressed:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim RabitAmount As Integer
Dim ShowEquation As String
[code]....
I got the equation to answer it self and show in the text box but it won't show the equation?
algebratic tecniques in VB, that don't work
View 3 RepliesI am looking for a way to simplify algebraic expressions in VB.NET. It is preferred if you can give me a link to a pre-written library or class.
View 1 RepliesSo I am trying to evaluate 3 conditions in an if statement. Its not working how I would assume it should. I basically want to do this:vb.net If PGN = &HEF007E And PGNData(0) = &H58 And (PGNData(1) And &H40) = &H40 Then IgnOn = True Else IgnOn = False If I write it in that manner it gives inconsistent results. If I workaround by writing it this way it works perfectly:vb.net If PGN = &HEF007E And PGNData(0) = &H58 Then If (PGNData(1) And &H40) = &H40 Then IgnOn = True Else IgnOn = False
View 1 RepliesDoes anybody know of a call in vb.net that will evaluate a string expression. For example, how would one evaluate the expression "(1+2)*(3+4)"?I've looked all over and it seems that people are writing their own parsers. There has to be a better way. After all these years, VB.Net must have something that will take an expression and evaluate it.
Dim strMyExpression as string = "(1+2)*(3+4)"
msgbox( VBEvaluate(strMyExpression))
and the result would be 35.Also, when will microsoft start to use google as the search engine for these forums? Bing really sucks. Searching for "Evaluating a string expression in VB.net" gives the most bizarre links.
My DGV's last visible column in a boolean. I am needing to go through each row and determine if the value of dgv item bFlag is true then turn the row back ground red. Here is my start of it. It appears to be only making one loop then giving the message box.
Private Sub EvalGrid()
BindDGV(dgvResults)
Dim cnt As Integer = dgvResults.Rows.Count
[Code]....
I am trying to figure out a way to set a string equal to vb code and then run that string as a line a of vb code.
for example
set string x = "TextBox1.Text =
"test1".ToString"
[code]....
I have a application that allows the user to enter a series of nested filtering commands. E.g "Name starts with x or ((Description contains y or Property1 is On) and Property2 > 100)"
I can preprocess this and distill it down to a string in the form of an expression of True and False's ie, To "True or ((False or True) and False)" Is there a simple way to have this final expression evaluated without having to write a complex evaluator myself?
I have seen a method of evaluating this by compiling a dummy function at runtime but as I need to process this against possibly thousands of records that solution is too slow.
BTW These are not all fields in a database so I cannot use Queries or SQL etc.
I'm working on a project where I need to evaluate some formulas in VB.NET. I've been using the MS Script Control to evaluate some of the simple logical/mathematical formulasHowever, I'm now faced with dealing with string expressions that set variables in my program to certain values. So, for example, let's say I've got the following:
Dim netPrice As Decimal
Dim expressionFormula As String = "netPrice = 0"
[code]....
Is there a method that allows me to evaluate a mathematical expression in a string? Example (Not actual Code):
Input = "2+2"
Output = SomeMethod(Input)
Output = 4
Update: Nevermind, I found a way around it by using DataTable.Compute.
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
With Me.PrintForm1
[Code]....
I'm looking to create an inline function (method) inside my NVelocity template. The solution to this appears to be to use Velocimacros. So, I mocked up the following template to test:
#macro( getOutput $one $two $three )
<td>$one</td>
<td>$two.Item2</td>
<td>$three</td>
#end
[Code] .....
When I run the template, the problem I'm having is that the output from the macro parameter $three is literally "$item.Item3" instead of evaluating to #3/3/2003#. (BTW - this happens with any of the 3 items in the tuple if they are passed with the .Item call, so it isn't about the data type). I can make a variable and pass it just fine ($one1). I can pass the tuple itself and call the .Item property inside the macro ($item.Item2), but for some reason I cannot call the .Item property when passing the argument to the macro.
We are working on a poker game as a class project. My part is to evaluate and then determine the value of a players hand. We are evaluating from highest to lowest (ie. determining whether the player has a straight flush, 4 of a kind, full house, flush and then going all the way down to a high card only "worthless hand"). My part is evaluating the 2 pair, 1 pair, and nothing hands. The hand will be a two-dimensional array with the row(0 thru 12),column (0) containing the numeric "face" value of the cards and the column(1) containing the value assigned to the suite (1=clubs, 2=diamonds,3=hearts,4=spades). I have NO IDEA where to even begin this evaluating procedure.
View 4 RepliesI am making a checkers program and I am in the phase of starting to evaluate jumps. This is what I currently have so far and allow me to fill you in a bit before you look at the code. Checker pieces are white/green. Each checker is created as a label at runtime and in the tag property a struct is held that possesses all of the information reguarding current and previous checker state.
The problem I am having is that as this sub runs each opposing checker is evaluated for jump capabilites which is all fine and dandy. It is even alright that currently if a jump is executed that the same side will continue to evaluate through the sub looking for additional jumps and if they are found they will be made because that is how it is currently coded. What I am trying to do is find a way to evaluate each piece that can jump. So if checker1 can only make one jump and checker2 can make a triple jump checker2 needs to be the guy making the jump and I honestly don't know how do start that. I am forseeing global vars being created to hold information or even a structure and taking the one that changes the most. If two checkers can only make 1 jump then I will rand the one that gets to jump (not looking to win any awards for AI here). Anyhow, any suggestions on how to start this, at least saving the information throughout the sub even if it is called recursively?
[Code]...
I'm working with visual studio 2008 developing software for windows CE 6.0, compact framework.I'm having this "strange?" trouble with isNumeric method. Is there another better way to do this job? Why is getting me an exception? (two in facts...both of type FormatException)
dim tmpStr as object = "Hello"
if isNumeric(tmpStr) then // EXCEPTIONs on this line
// It's a number
else
// it's a string
end if
[URL]From what we can see on MSDN, it says to be careful about which expressions we put as they change from language to language. My question is: what are the supported languages for writing those expressions? If various languages can do it, how does it detect which language is being used?I've made my class in CLI, and coded the expression in c#, being that it works. I've tried in c++/CLI, but that way it doesn't.
Here is my code:
[DebuggerDisplay("z = {ToString()} Norm = {System.Math.Round(Norm,2)} Angle = {System.Math.Round(Angle, 2)}")]
Now, trying it the c++/CLI way:
[DebuggerDisplay("z = {ToString()} Norm = {System::Math::Round(Norm,2)} Angle = {System::Math::Round(Angle, 2)}")]
My assumption is that it will always read the expression as c# code. Is this true?
I have an EnumerableRowCollection that looks like the following:
VendorCode | GroupType | Variance
01165 G .16
01165 G .16
01165 CH .16
01165 CH .18
07754 G .25
07754 G .25
07754 G .39
Essentially, this is a massive list of vendor codes, their groups, and price variances. I need to compose a query that will create a distinct list vendor codes and group types. The catch, however, is that I need to evaluate all of the variances associated with that particular VendorCode/GroupType to see if they are all the same - it they are not, I need to return some way of signifying that the group has a "custom" variance, otherwise it needs to return the value (ie: if they are all .16, then return .16, if there are multiple values, return "custom")
The result would look like this, based off of the list I showed above.
VendorCode | GroupType | Variance
01165 G .16
01165 CH custom
07754 G custom
I have no trouble getting a distinct list of VendorCode/GroupType - this is what I have so far:
Dim distinctList = From q In query Select q.VendorCode, q.GroupType, (evaluated q.Variance here?) Distinct
(where "query" is an EnumerableRowCollection(Of (anonymous type)))
I'm at a loss, though, on how to evaluate the variance property to get the result that I need?
Just switched over from VS2005 to VS2010 and I am having issues debugging my software. When I stop at a breakpoint, I can't see what variables contain. When I try to look at variables with QuickWatch, it states that it is "Unable to evaluate expression."
View 3 RepliesI want to iterate through an equation and modify a number e.g. Multiply it by 10, where there is one. How do I do this?
View 4 RepliesI wanted to read input equation by user A+B and assign input user value to A and B to ask them to add and give answer. But I just can't get the code to work. I using VS2005 and VB.Net.[code]
View 1 RepliesCan I use a function for more than one equation?
Program Description: Fortuitous Dice is a game that requires two dice be rolled, one at a time. If p and q are the numbers rolled on the first and second die, respectively the value of the roll in the game is determined as follows:
P Q Rule (value of the roll and condition)
Even Odd 2P + Q
Odd Even P + 2Q
Even Even P + Q When P not = Q
P When P = Q
odd Odd P + Q When P not = Q
3Q When P = Q
I have a decent understanding of the logic, the content. I'm working on a puzzle and I'd like to write a short program. I'm looking to fill in the following variables: AB.CDE FG.HIJ (they're part of coordinates, and the puzzle is part of a geocache)
The puzzle asks you to determine which numbers correspond to certain colors, like this:
[code...]
I need to define A-J as >= 0 and <=9. I also need to say that each color is >= 0 and <=9, but that no color can be equal to another color (purple ≠yellow, orange, etc). some number combinations won't work. Purple and yellow can't be 2 and 5 respectively, because that'd produce a negative number. I'm guessing that there will be more than one possible result. So how do I create an equation that calculates this.
I would like to read a user's input equation or expression as a string (such as "y=5*(x+6)" or "cos(3)^2") and have the program evaluate it mathematically. Does .Net have any classes that could do this? Obviously, the compiler can already take a programmer's coded equation and evaluate it. Of course this is a different matter, but is there not a way to harness that same power with runtime user-created equations? Serialization or anything?
The other option (I guess) would be to create my own equation-generator - breaking an equation down into a binary tree of the numerical values and the operations I suppose. Aside from being a nontrivial task, my program needs optimal performance as these equations are in large loops. At the very least, this would add several conditional evaluations to each equation run - dunno if that adds up.
The project is "kWh counter", that is, a simple program that calculates the power usage.The incoming numbers are the Power of the appliance (lightbulb) and the voltage (230/120).The formula is W=P*t that is multiplication of the power and the time it is used.I thought to connect it with a timer and the passing secconds multyply with the power, and, write the ussage on a label.This would be something like a simple digital power counter.Note that the voltage is not necesary.I am from europe where the standards are 230V.
View 7 RepliesI have an equation in the form of a string:
Dim Answer as Integer
Dim AnswerBox as New RichTextBox
'... Settings for AnswerBox
[code].....
My assignment is to get the Get Monthly Income (Num1)Get Monthly Home Rent/Mortgage (Num2) Get Other Monthly Payments (alimony, child support, student loans) (Num3) Display Allowable Monthly Car Payment Display Maximum Car Value (interest rate based on credit) (answer) Public Class Form1
[Code]...
What I need to do is automatically generate a specific PIN number based on the current date. The formula goes like this: MMDD + 1234 = PIN. (ex. Date = 3/26/2012 -> 0326 + 1234 = 1560; With 1560 being the PIN number. I then need the PIN number to display as text, but that's the easy part, I really just need assistance with getting the date information in the proper format for the equation.
View 2 Repliesafter a lot of research on formatting Maths equations, apparently using MS equation edior is the easiest way to do it. But, I have no idea how to use it in VS 2008.
View 2 Replies