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Hi, New here, and would be very thankful for any help someone can give me.
The code I am working for is a population estimator. It has 3 text boxes, the first is two enter the starting population, the second is to enter the daily increase in that population in a percentage, and the third is the number of days to multiply that by.
My first issue is with the second text box. I don't know how to enter the data as a percent. As of now it is only entering as a whole number, so I when I right in text box one the number 2, in box2 the number 30, and in three the number 10, I get the 302. Not 21.209 like it should be.
Secondly, it all displays in a listbox, and its supposed to loop for every day you enter. I've got the loop to loop by days, but it just runs the same calculation, I want it make every entry build off the last.
Example:
It should say
2
2.6
3.38
4.394
5.7122
etc
I've entered in the code below.
Thanks for any help!
private void calculateButton_Click(object sender, EventArgs e)
{
int organisms;
int days;
int growth;
int population;
int count = 1;
if (int.TryParse(OrganismsTextbox.Text, out organisms))
{
if (int.TryParse(DailyTextbox.Text, out growth ))
{
if (int.TryParse(DaysTextbox.Text, out days))
do
{
population = organisms + growth * days;
resultsListbox.Items.Add("The population For day " + count + " is " + population.ToString("n1"));
count = count + 1;
}
while (count <= days);
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You probably need to use double values rather than integers for your calculations, for greater accuracy. You also need to convert the number taken from the second textbox to a percentage; it's not 30 it is .30. You also need to change your calculation to calculate the growth in compound terms - I'm not sure of the actual formula.
One of these days I'm going to think of a really clever signature.
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There are a couple of simple things to do - firstly as Richard said, you need to use floating point values instead of integers:
2 + 30% is 2.6, but as an integer it is 2 again! 
The second is that you are looping through the days, so you don't need to include the number of days in each calculation - just use the result from the previous day.
The third is that when you want an increased value, you can't just multiply by the percentage - 2 * 30% is 0.6, so your increase is 0.6, not your population. To increase your population, multiply but 1.0 + the percentage.
Finally, there is a better way to loop through the days: use a for loop instead of a while:
for (int day = 1; day <= days; day++)
{
... calculate here
}
So, my version would be:
resultsListbox.Items.Add(string.Format("The population for day {0} is {1}", day, organisms));
organisms *= 1.0 + percent;
with percent adjusted to 0.3 as Richard suggested.
If you get an email telling you that you can catch Swine Flu from tinned pork then just delete it. It's Spam.
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Thanks guys! Got it to work!
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Glad to hear it!
If you get an email telling you that you can catch Swine Flu from tinned pork then just delete it. It's Spam.
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