HP 48gII hp 48gII_user's manual_English_E_HDPMSG48E67_V2.pdf - Page 703

„°@)@BRCH@ @)START @START Within the BRCH menu („°@)@BRCH@) the following keystrokes are available to generate START constructs (the symbol indicates cursor position): • „ @START NEXT : Starts the START...NEXT construct: START • , @START : Starts the START...STEP construct: START STEP The START...NEXT construct The general form of this statement is: start_value end_value START program_statements NEXT Because for this case the increment is 1, in order for the loop to end you should ensure that start_value < end_value. Otherwise you will produce what is called an infinite (never-ending) loop. Example - calculating of the summation S defined above The START...NEXT construct contains an index whose value is inaccessible to the user. Since for the calculation of the sum the index itself (k, in this case) is needed, we must create our own index, k, that we will increment within the loop each time the loop is executed. A possible implementation for the calculation of S is the program: « 0. DUP → n S k « 0. n START k SQ S + 1. 'k' STO+ 'S' STO NEXT S "S" →TAG » » Type the program in, and save it in a variable called @@@S1@@@. Here is a brief explanation of how the program works: 1. This program needs an integer number as input. Thus, before execution, that number (n) is in stack level 1. The program is then executed. Page 21-54