Hello guys,
im struggling with the following problem, maybe someone can help.
My plot (see the code below) is about the timeseries of a variable and i want to add a linear trend. What i already did is to figure out the necessary parameters a and b.
Is there a toolbox-function to plot a line with just these paramets requiered? Or is creating a vector out of these parameters and plotting this vector a better solution?
Any help is appreciated!
Thanks and cheers,
Tim
import cdstoolbox as ct
@ct.application(title='Zonal mean and trend')
@ct.output.livefigure()
def application():
data = ct.catalogue.retrieve(
'reanalysis-era5-land-monthly-means',
{
'variable': '2m_temperature',
'product_type': 'monthly_averaged_reanalysis',
'year': [
'2002','2003','2004','2005','2006','2007','2008','2009','2010','2011','2012',
],
'month': [
'01','02','03','04','05','06','07','08','09','10','11','12'
],
'time': '00:00',
}
)
temp = ct.cube.average(data, dim=['lat', 'lon'])
a, b, a_std, b_std = ct.stats.trend(
temp, slope_units='°C year-1')
fig = ct.chart.line(temp,
layout_kwargs = {
'title': 'Monthly average temperature',
'xaxis':{
'title': 'Time [years]',
'range': ['2001-07','2013-06']
},
'yaxis': {
'title': 'ERA5 2m Air temperature (°C)',
'range': [-10,1]
}
},
scatter_kwargs = {
'mode': 'lines'
}
)
return fig
2 Comments
Vivien MAVEL
Dear Tim,
I have added a trend line to your workflow in the following application:
https://cds.climate.copernicus.eu/toolbox-editor/168/forum_trend_line
The trick is to compute the linear fit of the your data using the ct.stats.extrapolate function and plot the fit.
fit = ct.stats.extrapolate( temp, date_range_kwargs= { 'start': start_date, 'end': end_date, 'periods': 2 }, func='linear' )Let me know if you have any question or want any further explanation.
Regards.
Vivien
Tim Usedly
Dear Vivien,
thanks, this is exactly what I want to plot. No further questions!
Thanks and regards,
Tim