UTable

Version 1.0
Douglas Developments

Overview
Quick Start
Detailed Reference
Troubleshooting
Why UTable is edit locked and what’s Source.zip?
Disclaimer
History
Revisions
Contact the developer

Overview

UTable is a table utility written in TI-BASIC that is designed to model the basic functionality of the table in the TI-86 and even expand upon its features. Here is an overview of its features and its weaknesses:

Fast as the TI-86's table.
Full divide by zero protection.
Allows for viewing of as many y= functions (y1, y2, ..., yn) as the calculator can handle.
Settings for narrow and wide columns.
Support for "big numbers", numbers that won't fit in the allotted screen space.
Does not support parametric or polar tables.
Does not support specifying a list of x values to be used, the "ask" feature of the TI-86 table.

Quick Start

This section is designed to help you get a table of values on TI-85's screen as quickly as possible. It is not designed to spell out all the details of the operation of this software. That is done in the Detailed Reference section below.

If your calculator is not already in Function mode, do so now by pressing 2ND and then MODE and selecting Func. UTable's operation is not affected by this setting, however selecting Function mode will allow you to bring up the y= editor in step two.
Put the equation whose values you want to examine in the y1= field found by pressing the GRAPH button and then F1.
Run Ultimate Table by either selecting UTable from the PRGM menu or by typing UTable in at the home screen.
Press F1 for Table. If an ERROR 14 UNDEFINED occurs, it is likely that initialization vector (variable name of uT) was not found or has been altered from its default configuration. This situation can easily be resolved by selecting Quit at the error condition, rerunning UTable, and then selecting Init from the main menu and then choosing Yes.

Detailed Reference

Upon running UTable, the main menu appears with options for Table, Setup, Init, About, and Quit. Each of these will be discussed in detail here.

Table

Selecting this option loads the actual table of values. If setup properly, it will allow you to evaluate several different y= functions at a specified range of values.

Summary of keys

EXIT
Returns to main menu.
UP and DOWN
Moves the position indicator up and down. When it gets to the top or the bottom of the screen and the UP or DOWN button, respectively, is pressed, the table scrolls up or down a single step.
LEFT and RIGHT
Causes the position indicator to move to the next column in the corresponding direction. If the position indicator is at the far right or left column and there are more functions to be displayed, the table will move to the appropriate function.
2ND
Moves the table up one screen.
ALPHA
Moves the table down one screen.
GRAPH
Moves the indicator to the far left of the table. Use this feature to quickly move to the y1 column if you are in, for example, y3.
STAT
Moves the indicator to the far right of the table. If #Func is set to 3, this would correspond to the column for y3.
ENTER
Displays a screen with some summary information about the table and the value x and the current y= equation. In the event that a complex number is generated by the function at the corresponding x value that is too large to fit on the bottom row of the main table screen, this screen will always show all the digits of the number. Press ENTER when finished to return to the table.

Setup

The Setup menu is composed of two submenus that allow you to customize the way the UTable formats, displays, and calculates the table. It is highly recommended that this be reviewed in its entirety so to be aware of the strengths and weaknesses of this software. Be sure to note the section called Big#. The commands are listed in the order in which they appear in they two consecutive submenus.

Exit
Returns to the main menu.
Start
This is the x value of which the table will start.
Step
This is the value by which x is incremented.
>>>
Switches to the other submenu.
#Func
UTable has no way of checking to see how equations have been entered into the y= screen. This setting allows you to tell UTable which equations have been defined so that it can to try to generate a table. By default this value is set to one. Thus the table will only allow you to try to generate a table of values for the y1 equation. However, if #Func was set to three, it would allow you to attempt to generate tables for y1, y2, and y3. Anytime you try to generate a table for an equation that is undefined, you will get an ERROR 14 UNDEFINED.
Div0
Sets the Div0S to either 1e-10 or 0 to enable or disable the divide by zero protection. The value of 1e-10 should suffice to prevent most divide by zero errors, but in the rare situation that this does not trap the error, changing the Div0S value to something a little larger should solve the problem. See Div0S (below) for further explanation.
Div0S
Short for Div0 Step, this tool can be used to prevent divide by zero errors. It works on the following concept. Suppose you tried to generate a table for the function y=1/x that included an entry for x=0. You would soon discover that an ERROR 02 DIV BY ZERO would be generated. However if you changed the Start value to something very close to zero, say 0.001, the table would be generated and you would find that UTable would return a rather large number and it will not produce the error. Div0S is the increment that is added to x; in this case it is 0.001. The value for Div0S is actually added to x every time before the function is evaluated whether or not Div0 is enabled or disabled. However since by default Div0S is set to zero, the divide by zero protection is effectively disabled.
Big#
In certain circumstances involving numbers with large numbers with many significant digits, UTable will appear to return incorrect values. Consider the following example. Try setting y1=pi*x^7 and the Start value to 100 and Cols set to 2 and then looking at the table. UTable would display 3.14159265 for a corresponding x value of 100. The reason for this is that UTable outputs the first ten characters of the formatted number to the screen and anything past that is automatically truncated. The simplest way to solve this problem is to force all the tabulated values to be displayed in scientific notation with four significant digits. Enabling Big# does exactly that.
Col
This setting determines the number of columns that the table displays at a time. By default this setting is set to Auto. This means that if #Func is set to one, two columns of values are displayed in the table. If #Func is greater than one, three columns of values are displayed in the table. However, if Col is set to 2, then there will always be two columns of values displayed as long as #Func is not set to zero.

Init

UTable makes extensive use of an initialization variable named uT. It is a vector that stores all of the settings for UTable. If this variable is accidentally deleted or you received UTable without the initialization variable, it is easily recreated by choosing Init from the main menu and then selecting Yes. You can also use Init to restore UTable to its default settings. Press ENTER to return to the main menu.

About

Traditional "about this software" screen. Press ENTER to return to the main menu.

Quit

Return to the home screen.

Troubleshooting

There are two major error conditions that can arise and create distress. They are the ERROR 14 UNDEFINED and the ERROR 02 DIV BY ZERO errors.

The ERROR 14 UNDEFINED error is the most common. This can be caused by several things. The most likely cause of this error is when the value of #Func does not correspond to the number of equations defined in the y= screen. If, for example, #Func is set to 1, you must have an equation defined for y1 in the y= screen. Or if you have #Func set to 3, you must have equations defined for y1, y2, and y3. This condition and be remedied by adjusting #Func, defining the appropriate y= equations, or by choosing Init from the main menu and ensuring that y1 is defined.

ERROR 14 UNDEFINED can also be caused by the absence of the initialization variable uT. The best way to fix this problem is to chose Init from the main menu.

ERROR 02 DIV BY ZERO is generated whenever the calculator tries to divide anything by zero. This can occur when you try to generate table. The best way to solve this problem is to enable the divide by zero protection using Div0.

Why UTable is edit locked and what’s Source.zip?

After any program is created, before it can be run it must be tokenized. This process happens automatically and for small programs, this amounts to a brief delay. However, for larger programs, it can take quite a while. By edit locking UTable, this process will never need to be done. Thus if you accidentally hit GOTO when prompted with an error message, the tokenize process will not have to be repeated.

Edit locking has its disadvantages. Obviously the source cannot be viewed, debugged, or studied. To resolve this issue, an unlocked copy of UTable as well as some additional documentation can be found in Source.zip. Note that the unlocked copy is named UTABLE as opposed to UTable. It is requested of you that you DO NOT distribute the unlocked copy of UTable for the reasons listed above. However, please feel free to distributed the locked copy.

Disclaimer

The author will not make any guarantees that this software will produce the expected results or the results implied by the software or this documentation because he does not want to be liable for any sort of problem that may arise. As with any tool, it's strengths and weaknesses should be studied before relying upon it. If you do this, UTable should perform as expected and the results it returns should prove valuable. At the time of this publication, there are no known bugs or errors besides the issue surrounding Big# (see above). If anything seems out of the ordinary, please send an email to the address below.

Distribution of this product is permitted and encouraged so long as the you only distribute the edit locked version.

History

Upon failing to find the perfect feature-laden table utility for the TI-85 graphing calculator, it was decided that one should be written. While UTable does not duplicate every feature of the TI-86 table, it is the best that can be done and still be written in TI-BASIC and be of a reasonable size. It was originally designed to have even more features. Parametric tables, Polar tables, and the ability to use a predetermined list of x values corresponding to their appropriate y values were all deleted features. This is because UTable would probably consume half the calculators 28K of usable memory if all this was supported. Considering that these features would hardly ever be used, they were not deemed worthwhile.

Revisions

1.0 - This is the first and hopefully the last version released.

Contact the Developer

I, Doug Murphy, wrote this program in its entirety. Should you find any bugs or think that this software should function differently or have any other comments or suggestions, please send an email to the address below. All suggestions will be considered and significant bugs will be investigated promptly.

Douglas_Developments@yahoo.com