Coronavirus

salarchaser

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Mathematics not your strong point either then. Im trying to explain to him why his assumption that a sudden rise in cases is not because the R number has to be greater than 1(which he seems to believe). It only has to be above zero, and depends on the number already positive.
My A level maths was some time ago admittedly.

By definition, for more than one person to be infected by 1 person, R must be greater than 1.
For numbers to increase, more than one person must be infected by one person. Ergo, R >1.

How would you attribute the increase?
 

Walleye

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Im slightly confused because you’ve just agreed with everything i’ve just said.
The example(the pub) I used was deliberately crude because I was making a mathematical point. In relation to July however(you said R was above 1 for both England and Wales....you said this was based on your graph, on the previous page). I said however the latest figures today are that Englands R rate is confirmed at present as between 0.8 and 1.0. Wales(as of 3 days ago) was actually between 0.6 and 0.8. I didnt publish these figures.....the boffins did.
I don't think I agreed with you on anything.
You are confusing the virus spreading and the R value.

At all values above 0 the virus spreads. That's not agreeing with you.

At R< 1, the decay in cases per day is exponential. At > 1 the increase is exponential. At exactly 1 the change is also exponential but the exponent is 1 which is why daily cases would flatline.
That's why the magic number is 1. It's the mathematical tipping point between exponential decay and exponential growth.
 

Safranfoer

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Im slightly confused because you’ve just agreed with everything i’ve just said.
The example(the pub) I used was deliberately crude because I was making a mathematical point. In relation to July however(you said R was above 1 for both England and Wales....you said this was based on your graph, on the previous page). I said however the latest figures today are that Englands R rate is confirmed at present as between 0.8 and 1.0. Wales(as of 3 days ago) was actually between 0.6 and 0.8. I didnt publish these figures.....the boffins did. Argue with them about it if you need an explanation, im just trying to point out why you dont need R>1 to potentially have a massive problem.
Explain what I’m missing. If R0 is below 1 and falling, the virus is in exponential decline and will fizzle out. If it is above 1 and rises, the virus is advancing and cases will exponentially rise. How can a line on a graph curve UP if cases are declining?

And why are you defending the point anyway, given the scientists believe the R is above 1?
 

MikeCC

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My A level maths was some time ago admittedly.

By definition, for more than one person to be infected by 1 person, R must be greater than 1.
For numbers to increase, more than one person must be infected by one person. Ergo, R >1.

How would you attribute the increase?
It wasnt me who said there was an ‘increase’....it was Walleye. He said the R number was greater than 1 for England and Wales. The latest figures in the last day or so however confirm theyre both below 1(0.8 - 1.0 for England, 0.6 - 0.8 for Wales). Ask Walleye why he thinks things have increased.....hes the man with a graph🤷‍♂️. I just pointed out mathematically why his theory of R>1 doesnt have to be in place for an outbreak....which by his own investigations he seems to have grasped....and now hes only arguing with himself.
 

MikeCC

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Explain what I’m missing. If R0 is below 1 and falling, the virus is in exponential decline and will fizzle out. If it is above 1 and rises, the virus is advancing and cases will exponentially rise. How can a line on a graph curve UP if cases are declining?

And why are you defending the point anyway, given the scientists believe the R is above 1?
You lot would argue with your own shadows. it wasnt ME who published the official R figures for England and Wales.....the ‘scientists’ that you refer to, did. Are you saying they just told us something they wanted us to hear? Ask Walleye....he disagrees with them and says its actually above 1, based on his ‘graph’.
 

Walleye

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It wasnt me who said there was an ‘increase’....it was Walleye. He said the R number was greater than 1 for England and Wales. The latest figures in the last day or so however confirm theyre both below 1(0.8 - 1.0 for England, 0.6 - 0.8 for Wales). Ask Walleye why he thinks things have increased.....hes the man with a graph🤷‍♂️. I just pointed out mathematically why his theory of R>1 doesnt have to be in place for an outbreak....which by his own investigations he seems to have grasped....and now hes only arguing with himself.
No. I've been arguing with the fact you said the magic number is not 1.

I also said I don't trust the government's numbers when they release contradicting data.
 

MikeCC

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No. I've been arguing with the fact you said the magic number is not 1.

I also said I don't trust the government's numbers when they release contradicting data.
The magic number isnt 1.

Personally(no disrespect)....i’ll go with the official stats on R rate however as opposed to yours....I mean no offence.
 

Walleye

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The magic number isnt 1.

Personally(no disrespect)....i’ll go with the official stats on R rate however as opposed to yours....I mean no offence.
No offence taken of course, but check your maths about the magic number.
 

salarchaser

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The magic number isnt 1.

Personally(no disrespect)....i’ll go with the official stats on R rate however as opposed to yours....I mean no offence.
Ill repeat the question walleye asked but you declined to answer.
If the magic number isnt 1, what is it.
You're keen to say what it isnt without offering what it is.

 
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MikeCC

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Ill repeat the question walleye asked but you declined to answer.
If the magic number isnt 1, what is it.
You're keen to say what it isnt without offering what it is.
Indeed....maths defo not your strong point. I didnt decline to answer it, its just bleedin obvious - Zero is the ‘best’ magic number you can get to. Anything above zero carries infection, whether its 0.1 or 0.9, and it depends on the number of people already infected. If you suddenly have a bunch of asymptomatic people return from Viva Espania who decide not to quarantine then it still spreads ragardless of whether its 1.0 or whether its 0.5. Hypothetically it will fizzle out eventually below 1.0 but that depends on new cases entering the country. You cant eradicate anything greater than zero. 1(in the UK) is only a dream number that suggests everythings hunky dorey. Its useless however if you cant control the rest of the world.
 

Safranfoer

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You lot would argue with your own shadows. it wasnt ME who published the official R figures for England and Wales.....the ‘scientists’ that you refer to, did. Are you saying they just told us something they wanted us to hear? Ask Walleye....he disagrees with them and says its actually above 1, based on his ‘graph’.
The scientists themselves say that the data lag means the R rate is higher than 1. That's the point. The same scientists say that the official figures are 0.8 to 1 but with the data lag they believe it is above 1.
 

paddymc

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Indeed....maths defo not your strong point. I didnt decline to answer it, its just bleedin obvious - Zero is the ‘best’ magic number you can get to. Anything above zero carries infection, whether its 0.1 or 0.9, and it depends on the number of people already infected. If you suddenly have a bunch of asymptomatic people return from Viva Espania who decide not to quarantine then it still spreads ragardless of whether its 1.0 or whether its 0.5. Hypothetically it will fizzle out eventually below 1.0 but that depends on new cases entering the country. You cant eradicate anything greater than zero. 1(in the UK) is only a dream number that suggests everythings hunky dorey. Its useless however if you cant control the rest of the world.
1.0 certainly is the magic number.

Above that we are bound for a further lockdown and the NHS will again be under threat. Below that and the infection is dwindling.

What is it that you do not get ?
 

SOS

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1,0 can not be the magic number as that would mean the virus would go on and on at the same rate .so it has to be below 1.0
 

carrowmore

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“A time delay between initial infection and the need for hospital care usually means it may take between two to three weeks for the changes in the spread of Covid-19 to be reflected in the estimates.

It added: "For this reason, Sage does not have confidence that R is currently below 1 in England.

"We would expect to see this change in transmission reflected in the R and growth rate published over the next few weeks."




Sent from my iPhone using Tapatalk
 

MikeCC

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1.0 certainly is the magic number.

Above that we are bound for a further lockdown and the NHS will again be under threat. Below that and the infection is dwindling.

What is it that you do not get ?
Because you cannot control what comes into the country. If new cases continue to enter the UK then it doesnt matter whether its below 1, it still spreads. Only multiplying by zero do you get to zero. Guys....this is simple maths!
 

paddymc

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Because you cannot control what comes into the country. If new cases continue to enter the UK then it doesnt matter whether its below 1, it still spreads. Only multiplying by zero do you get to zero. Guys....this is simple maths!
It seems you want to eradicate it by reducing the R rate to zero.(y)

The way to do that is with a vaccine, in the meantime we need to keep the R rate below the magical 1.0
 

MikeCC

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It seems you want to eradicate it by reducing the R rate to zero.(y)

The way to do that is with a vaccine, in the meantime we need to keep the R rate below the magical 1.0
Thats correct, R =1 means we’re effectively ‘ground zero’....its a stale mate. If you can reduce it below 1 then your heading in the right direction to eradication but it depends entirely on shutting of your country entirely from the rest of the world. Only then is it possible to achieve R nought. If you allow infections into the country(the asymptomatic Benidorm gang back who wont quarantine) then it doesnt matter whether your rate is 1.0 or 0.5, you still have transmission - 10 x 0.5 is still 5. 1.0 is only a sales figure which tells us its not getting ‘worse’.....its not a ‘magic’ figure. Disney stardust ‘magic’ gets better the closer you get to R nought but depends entirely on ‘blocking’ transmission routes. Are we going to shut our country off however??
 

paddymc

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Thats correct, R =1 means we’re effectively ‘ground zero’....its a stale mate. If you can reduce it below 1 then your heading in the right direction to eradication but it depends entirely on shutting of your country entirely from the rest of the world. Only then is it possible to achieve R nought. If you allow infections into the country(the asymptomatic Benidorm gang back who wont quarantine) then it doesnt matter whether your rate is 1.0 or 0.5, you still have transmission - 10 x 0.5 is still 5. 1.0 is only a sales figure which tells us its not getting ‘worse’.....its not a ‘magic’ figure. Disney stardust ‘magic’ gets better the closer you get to R nought but depends entirely on ‘blocking’ transmission routes. Are we going to shut our country off however??
No need to shut off from the rest of the world, only those countries who are more highly infected than us (y)

You will always have transmission, until the R rate reaches zero, thus keep it nelow 1.0 until we get a vaccine (y)
 

Safranfoer

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Coronavirus analysis: We're now at the limit of easing lockdown https://www.bbc.co.uk/news/uk-53612390

Question marks in here over whether children will now be allowed back to school - with the idea floated that if schools must open, should we close pubs again? All speculation obviously - but I hadn’t even considered the schools angle to this. If this is the limit of lockdown release - what WILL happen when school’s re-open and they are acting as large communities of vectors of transmission? If they don’t let kids return but keep pubs open, there’ll be rage. If they close the pubs to let schools re-open, there’ll be rage. If they close both there’ll be financial ruin. If they open both and the rate continues to rise, there’ll be rage and mass lockdown again. No winning here.
 

MikeCC

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No need to shut off from the rest of the world, only those countries who are more highly infected than us (y)

You will always have transmission, until the R rate reaches zero, thus keep it nelow 1.0 until we get a vaccine (y)
Halleluja😀......someone gets the maths as to why 1 is is not the magic number! Sorry Paddy....its not a dig.
 

AlanT

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I've had a few drinks tonight and have just caught up on the last 20 posts about R=1. My heads was spinning before, it's really spinning now 😵
There are valid points being made but I think the key thing is that its not just about the R number in isolation, its a combination of R number and number of current cases.

For example. If there were 5 million current cases of C-19 and the R=1, then the health service would be in a constant state of being overrun and stricter measures could be justified (as they would pass on to 5million etc). I'd personally be staying in the house as theres a fair chance of catching it. Thats despite R=1 feeling fairly 'safe' right? (5m is a lot of folk to potentially bump into)

If there were 5million cases with R=0.5, stricter measures could still be justified since 2.5m is still a lot of folk to pass it on to. So just because the R rate may be lowi as in this exampke there is still a high likelihood of bumping into someone with it and therefore I'd probably still stay in the house, again despite R=0.5 feeling 'really safe'

Now, if the were only 5000 cases and R=1 I'd be happy to go out although I wasn't happy to go out when there were 5m cases at R=1!

In fact, and weirdly, if the number of cases was only 5000 and the R number suddenly changed to R=3 I'd probably still go out for a while as it could take a bit of time reaching me depending on where the hotsports were!

So, the R number is just an indication of rate of change of transmission rate up or down at a point in time, and any decisions around it have to be tied in with how many are actually infected at that point. Theres no logic in the statememt that Im hearing a lot just now: 'the R number is low so its safe to go out'. Not if there are 10m cases if it its not!

R=1 is only significant in that it indicates steady state, somethings in control, but needs to be used with other factors

For R<1, the only difference between say R=0.1 and R=0.8 is just the length of time it would take to reach R0. Yes both are still propagating the virus but its not doing so at a sustainable rate and in both cases will eventually see the virus disappear.

Its a bit confusing but if the R number was to remain stable at R=0.8, the number of overall cases will keep going down as remember, anything less than R=1 is in decline. The bit thats hard is thinking that if numbers keep declining, even to a very low level, the expectation is that the R number will reduce to say R=0.1? Well not necessarily so. The R number is influenced by the measures that are in place and other conditions UV etc.
So even although R=0.8 will result in a smaller and smaller group, that tiny group will still pass it on at R=0.8 if the same measures and conditions in place, it doesn't matter that theres fewer of them.

So regarding people flying in people in from abroad if they are coming from countries with low infection rates and only a small proportion are actually infected then they shoul not affect our R number if they follow our measures (thats the key part).

Anyway, I might edit or delete tmrw cheers🥂
 

MikeCC

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I've had a few drinks tonight and have just caught up on the last 20 posts about R=1. My heads was spinning before, it's really spinning now 😵
There are valid points being made but I think the key thing is that its not just about the R number in isolation, its a combination of R number and number of current cases.

For example. If there were 5 million current cases of C-19 and the R=1, then the health service would be in a constant state of being overrun and stricter measures could be justified (as they would pass on to 5million etc). I'd personally be staying in the house as theres a fair chance of catching it. Thats despite R=1 feeling fairly 'safe' right? (5m is a lot of folk to potentially bump into)

If there were 5million cases with R=0.5, stricter measures could still be justified since 2.5m is still a lot of folk to pass it on to. So just because the R rate may be lowi as in this exampke there is still a high likelihood of bumping into someone with it and therefore I'd probably still stay in the house, again despite R=0.5 feeling 'really safe'

Now, if the were only 5000 cases and R=1 I'd be happy to go out although I wasn't happy to go out when there were 5m cases at R=1!

In fact, and weirdly, if the number of cases was only 5000 and the R number suddenly changed to R=3 I'd probably still go out for a while as it could take a bit of time reaching me depending on where the hotsports were!

So, the R number is just an indication of rate of change of transmission rate up or down at a point in time, and any decisions around it have to be tied in with how many are actually infected at that point. Theres no logic in the statememt that Im hearing a lot just now: 'the R number is low so its safe to go out'. Not if there are 10m cases if it its not!

R=1 is only significant in that it indicates steady state, somethings in control, but needs to be used with other factors

For R<1, the only difference between say R=0.1 and R=0.8 is just the length of time it would take to reach R0. Yes both are still propagating the virus but its not doing so at a sustainable rate and in both cases will eventually see the virus disappear.

Its a bit confusing but if the R number was to remain stable at R=0.8, the number of overall cases will keep going down as remember, anything less than R=1 is in decline. The bit thats hard is thinking that if numbers keep declining, even to a very low level, the expectation is that the R number will reduce to say R=0.1? Well not necessarily so. The R number is influenced by the measures that are in place and other conditions UV etc.
So even although R=0.8 will result in a smaller and smaller group, that tiny group will still pass it on at R=0.8 if the same measures and conditions in place, it doesn't matter that theres fewer of them.

So regarding people flying in people in from abroad if they are coming from countries with low infection rates and only a small proportion are actually infected then they shoul not affect our R number if they follow our measures (thats the key part).

Anyway, I might edit or delete tmrw cheers🥂
Alan, yes......you totally get it. R zero is what your trying to achieve but can only be achieved if you keep the same group of people constant, both in terms of who they are and number they are. We cant do that however as people travel so therefore the constant changes. The travel inbound from abroad is the classic example where you a could have a high number of cases enter the country(the constant) at the one time and despite the fact your R number is below 1 you potentially still have a massive problem looming. This is why 1 is not a magic number, or indeed any number apart from zero. You have to control the constant, not just the R number.
 
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Walleye

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Alan, yes......you totally get it. R zero is what your trying to achieve but can only be achieved if you keep the same group of people constant, both in terms of who they are and number they are. We cant do that however as people travel so therefore the constant changes. The travel inbound from abroad is the classic example where you a could have a high number of cases enter the country(the constant) at the one time and despite the fact your R number is below 1 you potentially still have a massive problem looming. This is why 1 is not a magic number, or indeed any number apart from zero. You have to control the constant, not just the R number.
Nope.
I'll try to explain it again....
Nah, can't be arsed.
 
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