Web Service "plus"

This function adds two numbers together and provides the sum. It uses the built-in Water "plus" command. To try the example, copy and paste it into your Steam XML IDE. After you have pasted it into your Steam XML IDE, try double-clicking on open (left) angle brackets (<) to highlight a complete command or function.

Factorial

The factorial is a function that computes N x (N-1) x (N-2) ... (0).

To run the example, copy it into the Steam IDE. This example computes the factorial of 7, but that could be changed to any number up to 13.

Prime Number Sieve

This is a a single method that finds the prime numbers up to an endpoint using the Sieve of Eratosthenes.

To run the example, paste it into the Steam XML IDE and call it with " <find_primes 35>" as shown below, where 35 is an example of an endpoint. Using endpoints greater that 1000 may run slowly.

<defmethod find_primes endpoint>  <set primes=<vector/> result=<vector/>/> <do repeat=endpoint.<minus 1/>> primes.<insert <vector counter.<plus 2/> 1/> /> </do> primes.<for_each returns="all_except_null"> <do> <set count_times_val=counter.<plus 2/>.<times value.0/>/> <while count_times_val.<less_or_equal endpoint/> > </while> <set index = count_times_val.<minus 2/> />  primes.<get index/>.<set 1=0/> </do> <if> value.1.<more 0/> value.0 else null </if> </for_each> </defmethod> <find_primes 35/>

Mortgage Payment Calculator

This program provides a server for calculating monthly mortgage payments and provides a browser interface to access it. A level payment is assumed for a loan of a specified principal amount for a specified term expressed in whole months at a simple annual interest rate. First, the user submits a background color for the form. The color state information is stored in the page as a "hidden input".

<defclass level_amortization_payment>  
   <defmethod start
    background_color="white">  
    <BODY bgcolor=background_color>
     <FORM action="/get_inputs">
      Select Background Color <BR/>
      <INPUT type="radio" name="background_color"
       value="white" checked=true />White <BR/>
      <INPUT type="radio" name="background_color"
       value="red"/>Red <BR/>
      <INPUT type="radio" name="background_color"
       value="green"/>Green <BR/>
      <INPUT type="radio" name="background_color"
       value="blue"/>Blue <BR/>
      <BR/><BR/><BR/>
      <INPUT type="submit" value="Submit"/>
     </FORM>
    </BODY>
   </defmethod>

<defmethod get_inputs background_color>
    <BODY bgcolor=background_color>
     <FORM action="/amort">
      Loan Principal Amount $ <INPUT name="principal" value=100000/> <BR/>
      Loan Term (whole months) <INPUT name="term" value=12/> <BR/>
      Loan per Annum Interest Rate <INPUT name="annual_rate" value=10/>
      <BR/>
      <INPUT name="background_color" type="hidden"
       value=background_color/>  
      <BR/><BR/>
      <INPUT type="submit" value="Calculate Payment"/>
     </FORM>
    </BODY>
   </defmethod>

<defmethod amort principal term annual_rate background_color>
    <BODY bgcolor=background_color>
     <FORM action="/start">
      <H3> Principal Amount: $<do principal/> </H3>
      <H3> Term: <do term/> Months</H3>
      <H3> Simple Annual Interest Rate: <do annual_rate/>% </H3>
      <H3> Monthly Interest Rate: <do annual_rate.<divide 12/> />% </H3>
      <H3> Your Monthly Payment: $<do .<level_payment
       principal term annual_rate/>/> </H3>
      <INPUT name="background_color" type="hidden"
       value=background_color/>  
      <INPUT type="submit" value="Revise Inputs"/>
     </FORM>
    </BODY>
   </defmethod>

<defmethod level_payment principal term annual_rate>
    <set Im= 1.<plus annual_rate.<divide 1200/>/>/>
     principal.
      <times Im.<power term/>.
       <times Im.<minus 1/>.
        <divide Im.<power term/>.<minus 1/>/>/>/>
   </defmethod>

</defclass>

<open_browser_window "http://localhost:9090/"/>