[BUG] - θ not displayed properly on CAS screen

[Matt]

Software version 2013 11 25 (5447)
CAS version 1.1.0-27

To reproduce the bug:
1) start the polar app
2) switch to CAS mode
3) press the 'x t θ n' button.

θ should be displayed, but I get a rectangle like this [] instead.

[Mark Hardman]

(12-26-2013 06:25 PM)Matt Wrote:  Software version 2013 11 25 (5447)
CAS version 1.1.0-27

To reproduce the bug:
1) start the polar app
2) switch to CAS mode
3) press the 'x t θ n' button.

θ should be displayed, but I get a rectangle like this [] instead.

This bug was previously reported by Thomas Ritschel in the old forum: [HP Prime] CAS font problem.

The one response suggests that the problem can be resolved with a "hard reset". I don't think that is correct. From my experience, the bug is persistent, reproducible and continues to exist in the 2013 11 25 firmware.

Mark Hardman

[John Colvin]

I think that the x n T theta key was intended to be used within the app, not after
the app has been closed. The theta symbol always appears for me when running
the polar app, even if I run it while in the CAS mode.

[Mark Hardman]

(12-26-2013 11:28 PM)John Colvin Wrote:  I think that the x n T theta key was intended to be used within the app, not after
the app has been closed. The theta symbol always appears for me when running
the polar app, even if I run it while in the CAS mode.

Sorry, you can switch apps but you can never close an app. If I run the Polar app and suddenly want to simplify a function before adding it as R1. I should be able to press CAS and use its capabilities with theta being the variable of reference and then return to the Polar Symbolic View by pressing the Symb key. This currently works OK with the exception of the theta Unicode character not getting correctly rendered while in CAS mode.

Mark Hardman

[Mark Hardman]

(12-26-2013 11:28 PM)John Colvin Wrote:  The theta symbol always appears for me when running
the polar app, even if I run it while in the CAS mode.

Are you using the emulator or a physical Prime?

I can reproduce the bug on the actual hardware but not in the emulator.

Mark Hardman

[Matt]

Thanks for your comments so far. I should have checked the old forum first.

Theta does appear in the emulator (with latest firmware) just not the actual calculator.
As Mark said, you can't close an app. If you run the Parametric app then go to CAS and press 'x t θ n' you should get 't'. Run the Sequence app, switch to CAS and you'll get 'n'.
I think of it as the independent variable button.

But only 'x' works as a CAS variable.
So if you were in the Parametric app, then went to CAS and did diff(SIN(t)) you'll get 0 rather than COS(t).

[Han]

(12-27-2013 06:33 PM)Matt Wrote:  But only 'x' works as a CAS variable.
So if you were in the Parametric app, then went to CAS and did diff(SIN(t)) you'll get 0 rather than COS(t).

They can all be used as a CAS variable. For most CAS commands, \( x \) is the default variable where appropriate. The diff() command assumes \( x \) as the default variable of differentiation. However, diff(SIN(t),t) will work just fine (provided the variable \( t \) is used as part of the input).

[Matt]

(12-27-2013 06:36 PM)Han Wrote:  They can all be used as a CAS variable. For most CAS commands, \( x \) is the default variable where appropriate. The diff() command assumes \( x \) as the default variable of differentiation. However, diff(SIN(t),t) will work just fine (provided the variable \( t \) is used as part of the input).

Do you mean diff(SIN(t),t)?
diff(SIN(t)) doesn't work - it returns 0.

[Han]

(12-27-2013 06:43 PM)Matt Wrote:  

(12-27-2013 06:36 PM)Han Wrote:  They can all be used as a CAS variable. For most CAS commands, \( x \) is the default variable where appropriate. The diff() command assumes \( x \) as the default variable of differentiation. However, diff(SIN(t),t) will work just fine (provided the variable \( t \) is used as part of the input).

Do you mean diff(SIN(t),t)?
diff(SIN(t)) doesn't work - it returns 0.

diff(SIN(t)) assumes that the input variable is \( x \), so that \( sin(t) \) is just a constant (with respect to \(x\) ). The derivative is correct once you understand how diff() works when not all arguments are explicitly passed. On the other hand, diff(SIN(t),t) gives COS(t).

[John Colvin]

(12-27-2013 02:04 AM)Mark Hardman Wrote:  

(12-26-2013 11:28 PM)John Colvin Wrote:  The theta symbol always appears for me when running
the polar app, even if I run it while in the CAS mode.

Are you using the emulator or a physical Prime?

I can reproduce the bug on the actual hardware but not in the emulator.

Mark Hardman

I used my physical Prime, not the emulator. But let me clarify something. When in
polar mode, I was able to get the theta character while in Home (rpn) view, but the
symbol remained in the edit line when I switched over to CAS view. If I go directly
to CAS then I get the same [] that you talked about.