Logarithmic Scale X-Axis Visual Basic 2010 Express

EDN Admin · Jul 9, 2012

<span style="font-family:Verdana,sans-serif; font-size:9pt Hi there,
<span style="font-family:Verdana,sans-serif; font-size:9pt I have been programming a little bit in Visual Basic in 2010 but currently I have run into a problem. I am trying to plot data from a loaded file, however, I am trying to give the
user to determine whether they would like a linear graph or a log graph. Since I do not think you can change the chart at runtime, I have been trying to use two charts. If Linear is selected then the data would be plotted on chart 1 in a linear manner. If
Log is selected then it would plot the data on chart2 with a log scale x-axis. However, when I select islogarithmic to true in the chart controls and isstartedfromzero to false, I get an area saying that "Chart Area Axes - A logarithmic scale cannot be used
for this axis". I am not sure why. I have tried setting my own bounds and I have tried log scales with just one graph and it still comes up with the same error. My code works fine if its two linear graphs but if I set one to Logarithmic it errors out. The
error comes when the programs begins, not when the button is pushed and the data I am loading contains no zeroes or negative numbers.
<span style="font-family:Verdana,sans-serif; font-size:9pt
<span style="font-family:Verdana,sans-serif; font-size:9pt Here is my Code though :
<p style="line-height:normal; margin-bottom:0pt <span style="font-family:Consolas; color:blue; font-size:9.5pt Private<span style="font-family:Consolas; font-size:9.5pt
<span style="color:blue Sub Plot_Button(<span style="color:blue ByVal sender
<span style="color:blue As System.<span style="color:#2b91af Object,
<span style="color:blue ByVal e <span style="color:blue As System.

<span style="color:blue Dim X_axis_array() <span style="color:blue
As <span style="color:blue Double = <span style="color:blue Nothing, Y_axis_array()

<span style="color:blue Dim Plot_File_Data_Name_Selection 

<span style="color:blue Dim DtTest <span style="color:blue As
<span style="color:blue New <span style="color:#2b91af DataTable <span style="color:green
//Sets Dtest as a one new table of in-memory data; here so that it is refreshed everytime the Add_Data_Files_For_Plotting_Button is pushed.

<span style="color:blue Dim Plot_Data_File_Name <span style="color:blue
As <span style="color:blue String = 

FileOpen(1, Plot_File_Data_Name_Selection, 
<span style="color:green //Note that the first parameter assigns a file number, the second parameter specifies the file to open and the third specifies the File Open Mode - ie Input = read mode


<span style="color:blue If TextBox57.Text = 
 
z = 0


DtTest.Columns.Add(<span style="color:#a31515 "X_Array", 
DtTest.Columns.Add(<span style="color:#a31515 "Y_Array", <span style="color:blue
GetType(

 <span style="color:blue Dim dN
<span style="color:blue As <span style="color:blue Integer = 1

<span style="color:green //Now read the line(s) of text from the file until End of File (EOF) is reached


<span style="color:blue Do 
<span style="color:green //The Values are read as a string from the selected file, the string is seperated by using tab in the selected file.

<span style="color:blue Dim dummy_string = LineInput(1).Split(vbTab)



EOF(1)



<span style="color:#2b91af Array.Resize(Y_axis_array, z + dN)

<span style="color:blue End 
<span style="color:green //The String in Dummy String is converted to Double and passed to the x and y arrays

X_axis_array(z) = 
Y_axis_array(z) = 
<span style="color:green //The x array is plotted as the x-coordinate and the Y array is plotted as the Y-coordinate

DtTest.Rows.Add(X_axis_array(z), Y_axis_array(z))


z = z + 1




<span style="color:#2b91af Array.Resize(Y_axis_array, z)

FileClose(1)


.ChartType = DataVisualization.Charting.
.Points.DataBind(DtTest.DefaultView, <span style="color:#a31515 "X_Array",

.BorderWidth = 2

<span style="color:blue End 
<span style="color:blue ElseIf TextBox57.Text = <span style="color:#a31515
"Log" 

z = 0


DtTest.Columns.Add(<span style="color:#a31515 "X_Array", 
DtTest.Columns.Add(<span style="color:#a31515 "Y_Array", <span style="color:blue
GetType(

<span style="color:blue Dim dN <span style="color:blue As <span style="color:blue
Integer = 1

<span style="color:green //Now read the line(s) of text from the file until End of File (EOF) is reached


<span style="color:blue Do 
<span style="color:green //The Values are read as a string from the selected file, the string is seperated by using tab in the selected file.

<span style="color:blue Dim dummy_string = LineInput(1).Split(vbTab)



EOF(1)



<span style="color:#2b91af Array.Resize(Y_axis_array, z + dN)

<span style="color:blue End 
<span style="color:green //The String in Dummy String is converted to Double and passed to the x and y arrays

X_axis_array(z) = 
Y_axis_array(z) = 
<span style="color:green //The x array is plotted as the x-coordinate and the Y array is plotted as the Y-coordinate

DtTest.Rows.Add(X_axis_array(z), Y_axis_array(z))


z = z + 1




<span style="color:#2b91af Array.Resize(Y_axis_array, z)

FileClose(1)


.ChartType = DataVisualization.Charting.
.Points.DataBind(DtTest.DefaultView, <span style="color:#a31515 "X_Array",

.BorderWidth = 2

<span style="color:blue End 

MsgBox(
FileClose()



<span style="color:blue End <span style="color:blue Sub
<p style="line-height:normal; margin-bottom:0pt <span style="font-family:Consolas; font-size:9.5pt <span style="color:blue
<p style="line-height:normal; margin-bottom:0pt <span style="font-family:Consolas; font-size:9.5pt <span style="color:blue Thanks!

View the full article

Logarithmic Scale X-Axis Visual Basic 2010 Express

EDN Admin

Well-known member

Similar threads