Help with Adjusting axes of PlotItem object

[Andrew More]

I'd like to find a way to manually change the displayed values on the axes of a PlotItem without changing any aspect of how the data in the PlotItem is displayed. As far as I can tell, changing anything about the axes necessitates also shifting the values of the data so it displays properly, but I'd like to avoid this. Is there a way to do this?

[Martin Chase]

Hey Andrew,

I'm sorry, I'm unable to determine what you mean by "changing anything about the axes". Could you post sample code demonstrating what you're trying to do?

Best,

 - Martin

On Fri, Sep 6, 2024 at 10:05 AM Andrew More <andrew....@gmail.com> wrote:

I'd like to find a way to manually change the displayed values on the axes of a PlotItem without changing any aspect of how the data in the PlotItem is displayed. As far as I can tell, changing anything about the axes necessitates also shifting the values of the data so it displays properly, but I'd like to avoid this. Is there a way to do this?

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[Andrew More]

I am trying to determine a way to alter the numbers displayed on ticks of the axes of an ImageView object showing a PlotItem. However, I'd only like this change to be shown visually on the axis ticks and not change the shape, scope, or underlying calculations of the plotted data. As far as I can tell, manually accessing the axis objects with:
```python
plot = pg.PlotItem()
# Initialize ImageView with the custom PlotItem
view = pg.ImageView(view=plot)

# Access the x-axis (bottom axis) of the PlotItem
x_axis = plot.getAxis('bottom')

# Define custom tick positions and labels
ticks = [(50, '50'), (100, '100'), (150, '150'), (200, '200'), (250, '250')]

# Apply the custom ticks to the x-axis
x_axis.setTicks([ticks])

```
Would alter the X Axis ticks as desired, but would also manipulate data displayed in the underlying plot as it seems to take into account the axis object when displaying data.

Basically I would like to know if there's a way to create a visual change in the displayed axes without changing the underlying axis used to find the shape of the plot. Since the data I am trying to display will shift dynamically, I'd like to be able to change these axis ticks dynamically as well as follows:

```python
import PyQt6
import pyqtgraph as pg
import numpy as np

#Initializing plot item and image view structure
plot = pg.PlotItem()
view = pg.ImageView(view=plot)
view.imageItem.setImage(np.ones((2048,2048), dtype=np.uint8) * 255,autoRange=False)

#Depending on user interaction that image content will be changed
if (event_happens):
    view.imageItem.setImage(new_image_content, autoRange=False)
    ## Here I would like I way to change the displayed numbers on the axes of the ImageView object without affecting the displayed data

```

Please let me know if I need to offer further clarification of my question. Thank you