Error setting property 'YLabel' of class 'Axes':

I'm getting the error message:

Error setting property 'YLabel' of class 'Axes':

Value must be 'matlab.graphics.Graphics'

figure;
        ax = gca;
        ax.YLabel = "[Pressure [Pa]]"  ;

I do not understand the contents of the error message

What is wrong with the value, I try to assign?

I don't get any error message if I just use

   ylabel('[Pressure [Pa]]')

Answer 1

[Voss]

The YLabel is a text object. You mean to set its String property:

figure;
ax = gca;
ax.YLabel.String = "[Pressure [Pa]]"  ;

You can see other properties of ax.YLabel you might want to set as well (though not all of them are settable):

disp(properties(ax.YLabel))

    {'Color'              }
    {'Position'           }
    {'String'             }
    {'Interpreter'        }
    {'Extent'             }
    {'Rotation'           }
    {'FontName'           }
    {'FontUnits'          }
    {'FontSize'           }
    {'FontAngle'          }
    {'FontWeight'         }
    {'HorizontalAlignment'}
    {'VerticalAlignment'  }
    {'EdgeColor'          }
    {'LineStyle'          }
    {'LineWidth'          }
    {'BackgroundColor'    }
    {'Margin'             }
    {'Editing'            }
    {'Clipping'           }
    {'FontSmoothing'      }
    {'Interactions'       }
    {'Units'              }
    {'Children'           }
    {'Parent'             }
    {'Visible'            }
    {'HandleVisibility'   }
    {'ButtonDownFcn'      }
    {'ContextMenu'        }
    {'BusyAction'         }
    {'BeingDeleted'       }
    {'Interruptible'      }
    {'CreateFcn'          }
    {'DeleteFcn'          }
    {'Type'               }
    {'Tag'                }
    {'UserData'           }
    {'Selected'           }
    {'SelectionHighlight' }
    {'HitTest'            }
    {'PickableParts'      }

[Voss]

(@hans "Answer" moved here:)

@Voss

Ah, OK, thank You !!

thank You for this very clear answer, which gives me more insight into the structure of the settings

[Voss]

@hans You're welcome!

[Voss]

(@hans "Answer" moved here:)

@Voss

I have some more question regarding the same category:

using legend with an axis-handle

It works writing:

figure;ax=gca;ax.XLabel.String = 'Time [s]';

But it doesn't work

figure;ax=gca;ax.Legend.Location = 'east';

Here I need to include the command legend to generate the legend, before I can define the location.

figure;ax=gca;legend; ax.Legend.Location = 'east';

What is the general background behind this?

Is an XLabel created by default, so I can define the string, while a legend is not created by default?

[Voss]

"Is an XLabel created by default, so I can define the string, while a legend is not created by default?"

Yeah, that's essentially correct. As soon as an axes is created, it has an XLabel, YLabel, etc., but it has no Legend until one is created.

figure;
ax=gca;
ax.Legend % empty

ans = 
  0×0 empty GraphicsPlaceholder array.

leg = legend(); % create a legend (stored in the variable "leg")

ax.Legend % now ax has a Legend

ans = 
  Legend with properties:

         String: {}
       Location: 'northeast'
    Orientation: 'vertical'
       FontSize: 9
       Position: [0.7327 0.8568 0.1529 0.0439]
          Units: 'normalized'

  Show all properties

isequal(ax.Legend,leg) % it is the same object as "leg"

ans = logical
   1

[hans]

@Voss

Thank You again, supporting my understanding.

[Voss]

You're welcome!