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VB.net form for converting DMS to Decimal Degrees

I'm trying to create a simple form to convert degrees minutes seconds to decimal degrees, but I'm having trouble when converting negative numbers. When I try to convert -92 7 6.52 I get -91.8815222 but the answer should be -92.118478. Why is this simple formula not working?

Private Sub btnDecimal_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDecimal.Click

        'txtLatDecimal.Text = Math.Round(CInt(txtLatDegrees.Text) + (CInt(txtLatMin.Text) / 60) + (CDec(txtLatSec.Text) / 3600), 7)

        'txtLngDecimal.Text = Math.Round(CInt(txtLngDegrees.Text) + (CInt(txtLngMin.Text) / 60) + (CDec(txtLngSec.Text) / 3600), 7)

        txtLatDecimal.Text = Math.Round(((CDec(txtLatSec.Text) / 60) + CInt(txtLatMin.Text)) / 60 + CInt(txtLatDegrees.Text), 7)
        txtLngDecimal.Text = Math.Round(((CDec(txtLngSec.Text) / 60) + CInt(txtLngMin.Text)) / 60 + CInt(txtLngDegrees.Text), 7)

    End Sub

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Ioannis Paraskevopoulos

Hi,

You are adding positive numbers to negative, so the result is closer to zero:
6.52/60+7/60-92 results to -91.8815222.

Giannis

Arthur_Wood

You need to determine the sign of txtLngDegrees.Text and then apply that sign to the other parts of your formula. Thus your formula would become

-6.52/60 - 7/60 - 92 = -92.118478

AW

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Arthur_Wood

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Nate_LR

ASKER

Thanks

Arthur_Wood

Glad to be of assistance.

AW