How to plot surface plot

开发者_如何学JAVA

Is there an inbuilt / m file in Matlab to obtain the highly fluctuatiing and multiple peaks of the plot of an alpine function? I want to obtain a similar figure in 3D which is !alt text and

The formula (probably) is

z=sin(x1)sin(x2)\sqrt{x1x2}

How does one plot a surface plot for the major functions like alpine,rosenbrock, egg crate function etc in a colorful illustrative way. Kindly help with a sample code.

---

Well, you must create a meshgrid choosing the right sampling (in this example from -5 to 5 with a step of 0.1). In Z put the formula of your function Z = f(X,Y)

X=[-5:0.1:5]; %% The X-axis goes from the value of -5 to +5 with a step of 0.1 (100 points)
Y=[-5:0.1:5]; %% like the X-axis
[wx,wy]=meshgrid(X,Y); %% see [MATLAB documentation][1]
Z=sinc(sqrt((wx-5).^2+wy.^2)); %% this is an example formula, substitute it with YOUR formula
fig=surfl(wx,wy,Z); %% make a surface plot with lighting
shading interp; %% optional, try to remove it.
colormap hot; %% here you decide the colormap: hot is the one going from white to red
view(45,40) %% optional, select the angle of view

If you want a meaningful color just study the colormap function, it's very simple.

---

this may not be the answer you are looking for but i thought it might help you

i faced the same problem when i had to plot Kaplan Meier Survival Curve programmatically

what we did (me and my team) was first getting the formula then we contructed a datatable that used this formula.

the datatable once formed was the datasource for chart control where you can edit the visual output as preferred.

look at the code below (it is only part of it) to have an idea. if you need more code please let me know

  'Start generating the life tables

Dim myTable As New DataTable

myTable.Columns.Add("Survial Status")
myTable.Columns.Add("Remaining Patients")
myTable.Columns.Add("Survial Duration")
myTable.Columns.Add("Survial Propability")
myTable.Columns.Add("Cumulative Survial Propability")

Dim myFirstRow As DataRow = myTable.NewRow
myFirstRow.Item(0) = 1
myFirstRow.Item(1) = CasesCount
myFirstRow.Item(2) = 0
myFirstRow.Item(3) = 1
myFirstRow.Item(4) = 1

myTable.Rows.Add(myFirstRow)

Dim Ptnseq = CasesCount

For I = 1 To CasesCount

    Dim myRow As DataRow = myTable.NewRow

    'Get only one record  from KaplanTable
    Dim Kaplantmp = myReader.Read
    Ptnseq = Ptnseq - 1

    myRow.Item(0) = myReader.GetValue(2)
    myRow.Item(1) = Ptnseq 'Sets the total number of remaining patients
    myRow.Item(2) = myReader.GetValue(3)

    If myRow.Item(0) = 0 Then
        myRow.Item(3) = myTable.Rows(I - 1).Item(3)
        myRow.Item(4) = myTable.Rows(I - 1).Item(4)
    ElseIf myRow.Item(0) = 1 Then
        myRow.Item(3) = myRow.Item(1) / myTable.Rows(I - 1).Item(1)
        myRow.Item(4) = myRow.Item(3) * myTable.Rows(I - 1).Item(4)
    End If

    myTable.Rows.Add(myRow)

Next I

'Finished generating the lifetables, bind it to a grid

Dim myGrid As New GridView 'Create a new dynamc Grid
Dim myLabel As New Label 'Create a new dynamic label for this grid
myPage.Form.Controls.Add(myLabel) 'add the label, then
myPage.Form.Controls.Add(myGrid) 'add the grid
myGrid.DataSource = myTable 'Bind the grid to the calculated lifetables
myGrid.DataBind()

DrawKaplanCurve(myTable, myChart, Stratum)
myLabel.Text = "Current Stratum is: " & Stratum & "<br/>" & "Total Number of cases is: " & (myTable.Rows.Count - 1).ToString & " Cases"

Return myTable.Rows.Count - 1

End Function

Public Shared Sub DrawKaplanCurve(ByVal myTable As DataTable, ByVal myChart As Chart, ByVal Stratum As String)

Dim KaplanSeries As New Series
KaplanSeries.ChartType = SeriesChartType.StepLine
KaplanSeries.Name = Stratum

Dim CensoredSeries As New Series
CensoredSeries.ChartType = SeriesChartType.Stock
CensoredSeries.Name = "Censored " & Stratum

For I = 1 To myTable.Rows.Count - 1

    Dim myPoint As New DataPoint
    Dim xval As Double = myTable.Rows(I).Item(2)
    Dim yval As Double = myTable.Rows(I).Item(4)
    myPoint.SetValueXY(xval, yval)

    ' If alive case, then add to censored data
    If myTable.Rows(I).Item(0) = 0 Then
        Dim CensoredPoint As New DataPoint
        CensoredPoint.SetValueXY(myPoint.XValue, yval - 0.01, yval + 0.01)
        CensoredPoint.ToolTip = "Censored Case Number " & myTable.Rows(I).Item(1).ToString & vbNewLine & "Survival Duration = " & myTable.Rows(I).Item(2).ToString & " months" & vbNewLine & "Cumulative Survival Propability = " & Round(yval * 100, 2).ToString & "%"
        CensoredPoint.Color = myPoint.Color
        If I <> myTable.Rows.Count - 1 Then CensoredSeries.Points.Add(CensoredPoint) 'add all except the last point because it shouldn't be censored
    End If

    'myPoint.ToolTip = "Case Number " & myTable.Rows(I).Item(1).ToString & vbNewLine & "Survival Duration = " & myTable.Rows(I).Item(2).ToString & " months"
    If I = myTable.Rows.Count - 1 Then myPoint.Label = Round(yval * 100, 2).ToString & "%"
    KaplanSeries.Points.Add(myPoint)

Next

myChart.Series.Add(KaplanSeries)
myChart.Series.Add(CensoredSeries)
myChart.Series(CensoredSeries.Name).IsVisibleInLegend = False
Dim myLegend As New Legend
myLegend.TitleForeColor = myChart.Series(myChart.Series.Count - 1).Color
myChart.Legends.Add(myLegend)

End Sub