LabVIEW
How do I reach the Limits on a DBL Slider
If you want a solution that does not require any code changes, make an Xcontrol that handles all desired rounding internally and use it as a drop-in replacement.
Frankly, I don't understand your hangups here. As others have mentioned, 0.1 cannot be accurately represented in binary and there is no way around that. Do you really want LabVIEW to ignore standards that everybody else has agreed on? If you want different behavior, you need to program around it and there are plenty off suggestions.
If compilers would start correcting numbers internally by making assumptions about intent, chaos would ensue.
I haven't studied this, but maybe e.g. decimal64 could in the future solve your dillema this if it is ever adapted.
You can actually argue that the control is working as intended. See the "Increment/Decrement" help file here:
Using the Increment and Decrement Buttons
Using the Increment and Decrement Buttons
The increment and decrement buttons usually change the ones digit in a digital control. If you click an increment or decrement button and hold the mouse button down, the display increases or decreases until you release the mouse button. If you click the increment or decrement button, hold down the mouse button, and hold down the <Shift> key, the size of the increment increases by successively higher orders of magnitude. The value first increments by ones, then by tens, by hundreds, and so on. As the range limit approaches, the increment decreases by orders of magnitude, slowing down as the value reaches the limit.
To use the arrow keys to change a digital display by a digit other than the default increment, use the Operating tool to place the insertion point to the right of the target digit.
Complete the following steps to practice using the increment and decrement buttons.
- Place a digital control on the front panel.
Place
- Using the Operating tool, click the increment and decrement buttons. The value increases and decreases by one.
- Click and hold down the increment button to increase the value repeatedly.
- Using the Positioning tool, resize the digital control. Notice that the control can be increased in length only horizontally.
- Using the Operating tool again, hold down the <Shift> key while holding down the increment button. Notice that the value begins to increase by one, but then by tens, hundreds, and so on.
- Change the value of the digital control to 10 by double-clicking inside the display window, typing 10, and pressing the <Enter> key.
- Click the increment button two times. The value increases by one with each click and the value is now 12.
- To increment by tens, use the Operating tool to place an insertion point to the right of the tens digit. Press the up arrow key to increase the value to 22. By placing the insertion point to the right of the tens digit, the increment value is changed to tens.
- Move the insertion point to the right of the ones digit, and click the increment button. The value increments to 23. Notice that the ones digit again becomes the increment digit.
Right-click a numeric control and select Visible Items»Increment/Decrement from the shortcut menu to display or hide the increment and decrement buttons. You also can use the Increment/Decrement Visible? property to display or hide the buttons programmatically.
From what this says, I surmise that the Increment/Decrement value was never meant to be fractional. All the references are to integers. While it never states that fractional values aren't recommended, there are plenty of times it would infer this.
Bill
billko wrote:You can actually argue that the control is working as intended. See the "Increment/Decrement" help file here:
Using the Increment and Decrement Buttons
Using the Increment and Decrement Buttons
The increment and decrement buttons usually change the ones digit in a digital control. If you click an increment or decrement button and hold the mouse button down, the display increases or decreases until you release the mouse button. If you click the increment or decrement button, hold down the mouse button, and hold down the <Shift> key, the size of the increment increases by successively higher orders of magnitude. The value first increments by ones, then by tens, by hundreds, and so on. As the range limit approaches, the increment decreases by orders of magnitude, slowing down as the value reaches the limit.
To use the arrow keys to change a digital display by a digit other than the default increment, use the Operating tool to place the insertion point to the right of the target digit.
Complete the following steps to practice using the increment and decrement buttons.
- Place a digital control on the front panel.
- Using the Operating tool, click the increment and decrement buttons. The value increases and decreases by one.
- Click and hold down the increment button to increase the value repeatedly.
- Using the Positioning tool, resize the digital control. Notice that the control can be increased in length only horizontally.
- Using the Operating tool again, hold down the <Shift> key while holding down the increment button. Notice that the value begins to increase by one, but then by tens, hundreds, and so on.
- Change the value of the digital control to 10 by double-clicking inside the display window, typing 10, and pressing the <Enter> key.
- Click the increment button two times. The value increases by one with each click and the value is now 12.
- To increment by tens, use the Operating tool to place an insertion point to the right of the tens digit. Press the up arrow key to increase the value to 22. By placing the insertion point to the right of the tens digit, the increment value is changed to tens.
- Move the insertion point to the right of the ones digit, and click the increment button. The value increments to 23. Notice that the ones digit again becomes the increment digit.
Right-click a numeric control and select Visible Items»Increment/Decrement from the shortcut menu to display or hide the increment and decrement buttons. You also can use the Increment/Decrement Visible? property to display or hide the buttons programmatically.
From what this says, I surmise that the Increment/Decrement value was never meant to be fractional. All the references are to integers. While it never states that fractional values aren't recommended, there are plenty of times it would infer this.
Bill
But what I think is confusing is that the Property itself is a dbl and so you'd think fractional values were okay. Unless, of course, you were pretty sharp and noticed that dbl isn't going to give you exact increments sometimes.
