I'm trying to read two matrix from a binary file (256x256x2) but couldn't do it without iterating 256x256x2 times which takes too long. For now I just want to check the data and make sure it's corect (not only zeros). This is what I have:
Dim msg As String
Dim b(256 * 256 * 2) As Byte
Dim i As Int32
Dim reader As New BinaryReader(File.Open(path, FileMode.Open))
b = reader.ReadBytes(b.Length)
For i = 0 To b.Length
msg = msg & ", " & b(i)
Next
TextBox1.Text = msg
The data on the matrix are just numbers (0-255).
What's the best way to save the data to an array, if possible with the format
array[matrixno][row][column]
because later I will need to find specific values of the array based on its position.
PS. I'm using the old Visual Studio 2003 because that's what I have available.
Thanks
Edit:
Figured out what was taking long was actually displaying all the bytes, problem solved!
Almost two years later, it's time to take this off the unanswered list.
The loop worked just fine, the problem was printing every single value read instead of simpling saving it to a variable.
Lesson learned (long ago): Printing takes time.
Related
I'm working on this project, in Visual Basic:
Sub Main()
Dim i As Integer, j As Double
i = 1
Dim fileReader =
My.Computer.FileSystem.OpenTextFileReader("C:\text.txt")
For i = 1 To 3
Dim stringReader = fileReader.ReadLine()
j = j + CDbl(stringReader)
Next
Debug.Print(j)
End Sub
Which is supposed to read the first three lines of a text file containing:
37107287533902102798797998220837590246510135740250
46376937677490009712648124896970078050417018260538
74324986199524741059474233309513058123726617309629
Now when these numbers are added up, and the result is printed, it gives me scientific notation, so here is my question:
Is there a way I can make the program write the whole number without scientific notation, AND all the significant figures, I seem to get a problem where past 10 ~ 12 digits it's just all 0.
I know similar questions have been asked but I can't seem to find an answer to apply to my case, so I'm sorry if it is a duplicate.
You can use something like this. This will avoid E exponential format of numbers.
YourNumber.ToString(".################") 'No of digits = No of hashes #
I want my program to read a certain part of a huge txt file, change one value and save the file again.
The file that needs editing looks like this:
168575 = {
name="Hidda"
female=yes
dynasty=9601
religion="catholic"
culture="german"
father=168573
960.1.1 = {
birth=yes
}
1030.1.1 = {
death=yes
}
}
My VB program takes the IDs from the blocks it has to change from another textbox like this.
31060
106551
106550
168575
40713
106523
106522
106555
As you can see, the number I want changed is in the middle of the textbox, the code I use to get the number from the line and look for it in the huge file is
Dim strText() As String
strText = Split(chars.Text, vbCrLf)
and later
If line.Contains(strText(0) & " = {") Then
TextBox1.AppendText(line & Environment.NewLine)
To form a code like:
Dim strText() As String
strText = Split(chars.Text, vbCrLf)
Label4.Text = strText(0)
Dim line As String = Nothing
Dim lines2 As Integer = 0
Using reader2 As New StreamReader("c:/dutch.txt")
While (reader2.Peek() <> -1)
line = reader2.ReadLine()
If line.Contains(strText(0) & " = {") Then
TextBox1.AppendText(line & Environment.NewLine)
End If
lines2 = lines2 + 1
Label2.Text = lines2
End While
End Using
Naturally, this only writes in a textbox the line that it found, how do I get the whole code with that IDs I take from 1 textbox, change the culture to another value and save it again? And repeat this for all the IDs in a textbox? Im not a coding legend but this has been bothering me for ages now :(
There are a few issues to consider here. If you're dealing with a large text file as a "database" and you wish to edit only parts of it without affecting the other parts, then you may wish to investigate editing it as a binary file instead of as a text stream. This has several downsides, however, since it means that you have to be aware of how big your records are and deal with things like padding.
If you can spare the disk IO and RAM (I don't know how huge you mean when you say huge) it would probably be vastly easier to simply load the entire file into an array or List(Of String), find the line representing the person, seek a few lines below that for the field you want (you said culture), change that field in the array or List, and then just resave the entire array or List back to a text file. This would make it fairly easy to do inserts and you wouldn't have to worry about padding, mostly you'd just have to worry about the line endings and the file encoding (and the amount of disk IO and RAM).
Finally, I would suggest that using a custom format text file as a database is generally a "bad" idea in 2014 unless you have a really good reason to be doing that. Your format looks very similar to JSON - perhaps you could consider using that instead of your existing format. Then there would be libraries such as JSON.Net to help you do the right thing and you wouldn't need to do any custom IO code.
I have a text file that has multiple blank lines and Im trying to return all the lines between two of them specifically
so if I have a file that looks like this:
____________________________
1########################
2##########################
3
4########################
5##########################
6#######################
7
8#########################
9##########################
10#######################
11####################
12########################
13#########################
14
15##########################
----------------------------
I would like to grab lines 8-13. Unfortunately, it might not always be 8-13 as it could be 9-20 or 7-8, but it will however always be between the 2nd and 3rd line break.
I know how to trim characters and pull out singular lines, but I have no idea how to trim entire sections.
Any help would be appreciated, even if you just point me to a tutorial.
Thanks in advance.
The basic idea here is to get the entire thing as a string, split it into groups at the double line breaks, and then reference the group you want (in your case, the third one).
Dim value As String = File.ReadAllText("C:\test.txt")
Dim breakString As String = Environment.NewLine & Environment.NewLine
Dim groups As String() = value.Split({breakString}, StringSplitOptions.None)
Dim desiredString As String = groups(2)
MsgBox(desiredString)
Edit:
In response to the question in your comment -
Environment.NewLine is a more dynamic way of specifying a line break. Assuming you're running on windows - you could use VbCrLf as well. The idea is that if you were to compile the same code on Linux, it Environment.NewLine would generate a Lf instead. You can see here for more information: http://en.wikipedia.org/wiki/Newline
The reason I used Environment.NewLine & Environment.NewLine is because you want to break your information where there are two line breaks (one at the end of the last line of a paragraph, and one for the blank line before the next paragraph)
What I ended up doing was trimming the last part and searching for what I needed in the first part (I know I didnt include the searching part in the question, but I was just trying to figure out a way to narrow down the search results as it would have had repeated results). Im posting this incase anyone else stumbles upon this looking for some answers.
Dim applist() = System.IO.File.ReadAllLines("C:\applist.txt")
Dim findICSName As String = "pid"
Dim ICSName As New Regex("\:.*?\(")
Dim x = 0
Do Until applist(x).Contains("Total PSS by OOM adjustment:")
If applist(x).Contains(findICSName) Then
app = ICSName.Match(applist(x)).Value
app = app.TrimStart(CChar(": "))
app = app.TrimEnd(CChar("("))
ListBox1.Items.Add(app)
End If
x = x + 1
Loop
End If
How this works is that it looks through each line for the regex until it reaches first word in the breakpoint "Total PSS by OOM adjustment:"
first time questioner here. Thanks in advance for any help you can give.
I'm trying to read a bunch of data from a spreadsheet, chop it up, then throw it into a database. I would rather not do things this way, but it's a basic reality of dealing with accountant-types. Thankfully these spreadsheet reports are very consistent. Anyway, I'm using LINQ for SQL to handle the object-to-reference stuff and I'm using Microsoft.Office.Interop to get my Excel on.
I read through a directory full of .xls and for each one, I'm opening the file, getting a couple of specific data from some specific cells, and then getting a range of cells to pick out values.
Private Sub ProcessAFile(ByVal f As FileInfo)
thisFile = openApp.Workbooks.Open(f.fullName)
thisMonth = Split(thisChart.Range("D6").Value, "-").Last.Trim
thisFY = thisChart.Range("L7").Value
thisWorkArea = thisChart.Range("A14", "L51").Value2
openApp.Workbooks.Close()
...
thisWorkArea was Dimmed as a global:
Dim thisWorkArea As Object(,)
I'm getting both strings and ints in my range between A14 and L51, so making it an Object array makes sense here. I don't want to go through each row and pick out ranges in Excel, I want to just read it once and then close it.
So I'm getting the following exception:
System.IndexOutOfRangeException was unhandled
Message=Index was outside the bounds of the array.
in this function:
Private Sub fillCurrMonth()
Dim theseRows As Integer() = {0, 2, 3, 5}
For Each i In theseRows
Dim thisMonth As New Month
'make sure category is in Database
thisMonth.Dept = thisDeptName
thisMonth.FY = thisFY
thisMonth.Category = thisWorkArea(i, 0)
...
"Month" above refers to a LINQ entity. It's nothing fancy.
That last line there is where I'm catching the exception. In my watch, I find that thisWorkArea has a length of 456 and (0,0) -> "Inpatient"{String}
So why am I getting this exception? I put this in your expert hands. I'm still rather new to vb.net, so maybe I'm just missing something fundamental.
Excel uses 1-based indicies. This stems from it using VB as it's in-app programming language which traditionally used 1-based indicies.
You'll find Excel returned an array defined as thisWorkArea(1 To 11, 1 To 37) As Object
'Fix excel's 1 based index
Dim oData(UBound(xData) - 1, UBound(xData, 2) - 1) As Object
For i As Integer = 1 To UBound(xData)
For ii As Integer = 1 To UBound(xData, 2)
oData(i - 1, ii - 1) = xData(i, ii)
Next
Next
I need your help, guys! :|
I've got myself a CSV file with the following contents:
1,The Compact,1.8GHz,1024MB,160GB,440
2,The Medium,2.4GHz,1024MB,180GB,500
3,The Workhorse,2.4GHz,2048MB,220GB,650
It's a list of computer systems, basically, that the user can purchase.
I need to read this file, line-by-line, into an array. Let's call this array csvline().
The first line of the text file would stored in csvline(0). Line two would be stored in csvline(1). And so on. (I've started with zero because that's where VB starts its arrays). A drop-down list would then enable the user to select 1, 2 or 3 (or however many lines/systems are stored in the file). Upon selecting a number - say, 1 - csvline(0) would be displayed inside a textbox (textbox1, let's say). If 2 was selected, csvline(1) would be displayed, and so on.
It's not the formatting I need help with, though; that's the easy part. I just need someone to help teach me how to read a CSV file line-by-line, putting each line into a string array - csvlines(count) - then increment count by one so that the next line is read into another slot.
So far, I've been able to paste the numbers of each system into an combobox:
Using csvfileparser As New Microsoft.VisualBasic.FileIO.TextFieldParser _
("F:\folder\programname\programname\bin\Debug\systems.csv")
Dim csvalue As String()
csvfileparser.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
csvfileparser.Delimiters = New String() {","}
While Not csvfileparser.EndOfData
csvalue = csvfileparser.ReadFields()
combobox1.Items.Add(String.Format("{1}{0}", _
Environment.NewLine, _
csvalue(0)))
End While
End Using
But this only selects individual values. I need to figure out how selecting one of these numbers in the combobox can trigger textbox1 to be appended with just that line (I can handle the formatting, using the string.format stuff). If I try to do this using csvalue = csvtranslator.ReadLine , I get the following error message:
"Error 1 Value of type 'String' cannot be converted to '1-dimensional array of String'."
If I then put it as an array, ie: csvalue() = csvtranslator.ReadLine , I then get a different error message:
"Error 1 Number of indices is less than the number of dimensions of the indexed array."
What's the knack, guys? I've spent hours trying to figure this out.
Please go easy on me - and keep any responses ultra-simple for my newbie brain - I'm very new to all this programming malarkey and just starting out! :)
Structure systemstructure
Dim number As Byte
Dim name As String
Dim procspeed As String
Dim ram As String
Dim harddrive As String
Dim price As Integer
End Structure
Private Sub csvmanagement()
Dim systemspecs As New systemstructure
Using csvparser As New FileIO.TextFieldParser _
("F:\folder\programname\programname\bin\Debug\systems.csv")
Dim csvalue As String()
csvparser.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
csvparser.Delimiters = New String() {","}
csvalue = csvparser.ReadFields()
systemspecs.number = csvalue(0)
systemspecs.name = csvalue(1)
systemspecs.procspeed = csvalue(2)
systemspecs.ram = csvalue(3)
systemspecs.harddrive = csvalue(4)
systemspecs.optical = csvalue(5)
systemspecs.graphics = csvalue(6)
systemspecs.audio = csvalue(7)
systemspecs.monitor = csvalue(8)
systemspecs.software = csvalue(9)
systemspecs.price = csvalue(10)
While Not csvparser.EndOfData
csvalue = csvparser.ReadFields()
systemlist.Items.Add(systemspecs)
End While
End Using
End Sub
Edit:
Thanks for your help guys, I've managed to solve the problem now.
It was merely a matter calling loops at the right point in time.
I would recommend using FileHelpers to do the reading.
The binding shouldn't be an issue after that.
Here is the Quickstart for Delimited Records:
Dim engine As New FileHelperEngine(GetType( Customer))
// To Read Use:
Dim res As Customer() = DirectCast(engine.ReadFile("FileIn.txt"), Customer())
// To Write Use:
engine.WriteFile("FileOut.txt", res)
When you get the file read, put it into a normal class and just bind to the class or use the list of items you have to do custom stuff with the combobox. Basically, get it out of the file and into a real class asap, then things will be easier.
At least take a look at the library. After using it, we use a lot more simple flat files since it is so easy, and we haven't written a file access routine since (for that kinda stuff).
http://msdn.microsoft.com/en-us/library/microsoft.visualbasic.fileio.textfieldparser.aspx
I think your main problem is understanding how arrays work (hence the error message).
You can use split and join functions to convert strings into and out of arrays
dim s() as string = split("1,2,3",",") gives and array of strings with 3 elements
dim ss as string = join(s,",") gives you the string back
Firstly, it's actually really good that you are using the TextFieldParser for reading CSV files - most don't but you won't have to worry about extra commas and quoted text etc...
The Readline method only gives you the raw string, hence the "Error 1 Value of type 'String' cannot be converted to '1-dimensional array of String'."
What you may find easier with combo boxes etc is to use an object (e.g. 'systemspecs') rather than strings. Assign the CSV data to the objects and override the "ToString" method of the 'systemspecs' class to display in the combo box how you want with formatting etc. That way when you handle the SelectedIndexChanged event (or similar) you get the "SelectedItem" from the combo box (which can be Nothing so check) and cast it as the 'systemspecs' to use it. The advantage is that you are not restricted to display the exact data in the combo etc.
' in "systemspecs"...
Public Overrides Function ToString() As String
Return Name ' or whatever...
End Function ' ToString
e.g.
dim item as new systemspecs
item.ID = csvalue(1)
item.Name = csvalue(2)
' etc...
combobox1.Items.Add(item)
Let me know if that makes sense!
PK :-)