About Me

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Northglenn, Colorado, United States
I'm primarily a BI Developer on the Microsoft stack. I do sometimes touch upon other Microsoft stacks ( web development, application development, and sql server development).

Thursday, July 20, 2006

Grid View Problem

Well recently I've been trying to get my grid view to be specific, since their is a column I didn't want showing up. The problem that surfaced was that the first column name would never show up, and the second column name would then be placed over the first. I have looked for solutions, where people might have had problems with BoundFields, but found nothing. So, I decided to do another solution, which works in this case.

I take the data set I was using and make a copy of it, remove the column I didn't want, and then add the selectable column.

Tuesday, July 11, 2006


Source: http://idunno.org/displayBlog.aspx/2004071401

This is a cool and very useful feature in C#. If you need to convert something like a date value from a sql database and display it into a textbox, then this is what you were looking for, before, it would always put the time 12:00 AM in after the date.


DateOnly = new DateTime();
DateOnly = (DateTime)dr["DATE_APPROVED"];
this.TextBoxDate.Text = String.Format("{0:d}", DateOnly);

Here are some of it's formats and conversions

Formating Strings:
String.Format("--{1,10}--", "test");-- test--
String.Format("--{1,-10}--", "test");--test --

Formating Numbers:
(double 1.2345)
(int -12345)
(whole number)
eexponent / scientific{0:e}1.234500e+000-1.234500e+004
ffixed point{0:f}1.23-12345.00
rround trippable{0:r}1.23System.FormatException

Custom Formatting
(double 1234.56)
0zero placeholder{0:00.000}1234.560
#digit placeholder{0:#.##}1234.56
.decimal point placeholder{0:0.0}1234.6
,thousand separator{0:0,0}1,235

(double 1234.56)
0zero placeholder{0:00.000}1234.560
#digit placeholder{0:#.##}1234.56
.decimal point placeholder{0:0.0}1234.6
,thousand separator{0:0,0}1,235

(June 8, 1970 12:30:59)
dShort Date08/06/1970
DLong Date08 June 1970
tShort Time12:30
TLong Time12:30:59
fFull date and time08 June 1970 12:30
FFull date and time (long)08 June 1970 12:30:59
gDefault date and time08/06/1970 12:30
GDefault date and time (long)08/06/1970 12:30:59
MDay / Month8 June
rRFC1123 date stringMon, 08 Jun 1970 12:30:59 GMT
sSortable date/time1970-06-08T12:30:59
uUniversal time, local timezone1970-06-08 12:30:59Z
YMonth / YearJune 1970

(June 8, 1970 12:30:59)
dddShort Day NameMon
ddddFull Day NameMonday
hh2 digit hour12
HH2 digit hour (24 hour)12
mm2 digit minute30
MMMShort Month nameJun
MMMMMonth nameJune
yy2 digit year70
yyyy4 digit year1970
:seperator, e.g. {0:hh:mm:ss}12:30:59
/seperator, e.g. {0:dd/mm/yyyy}08/06/1970

Monday, July 10, 2006

Convergence theory for nonconvex stochastic programming with an application to mixed logit


Abstract Monte Carlo methods have extensively been used and studied in the area of stochastic programming. Their convergence properties typically consider global minimizers or first-order critical points of the sample average approximation (SAA) problems and minimizers of the true problem, and show that the former converge to the latter for increasing sample size. However, the assumption of global minimization essentially restricts the scope of these results to convex problems. We review and extend these results in two directions: we allow for local SAA minimizers of possibly nonconvex problems and prove, under suitable conditions, almost sure convergence of local second-order solutions of the SAA problem to second-order critical points of the true problem. We also apply this new theory to the estimation of mixed logit models for discrete choice analysis. New useful convergence properties are derived in this context, both for the constrained and unconstrained cases, and associated estimates of the simulation bias and variance are proposed.

Wednesday, July 05, 2006

On change event in ASP.Net

In ASP.Net the ontextchanged event doesn't get called until a postback, the problem we had was to ask the user before leaving the page, if they would like to save any of their changes that were made, and to enable the submit button if there were changes. We had to go to javascript, again, for this answer.

<script language="javascript" type="text/javascript">
window.onbeforeunload = saveChanges;
function saveChanges()
var changes = document.getElementById("<%=this.ButtonSubmit.ClientID%>").disabled;
event.returnValue = 'Changes were not saved. Click Cancel to go back and submit changes, or click OK to continue.';

function enableSubmit()
document.getElementById("<%=this.ButtonSubmit.ClientID%>").disabled = false;

The first function: saveChanges() is called when ever the user tries to change the current page or close the browser. It just asks if they user wants to leave without saving.

The second function is called when ever a textbox, or other asp/html control has changed. This basically just enables the submit button.

So, within the page we might have a ASP.Net control like this:

<asp:textbox id="TextBox1" runat="server" onchange="enableSubmit()" width="49px"><asp:textbox>

Now, you would end up getting a warning in ASP.Net since it doesn't recognize the onchange event, since this is actually a javascript event. The trick here is when the page is render this is how it would look in the html:

<input id="ctl00_ContentPlaceHolder1_TextBox1" style="WIDTH: 49px" onchange="enableSubmit()" name="ctl00$ContentPlaceHolder1$TextBoxNotes">